All language subtitles for Ancient.Invisible.Cities.S01E02.720p.AMZN.WEBRip.x264-GalaxyTV Eng

DR MICHAEL SCOTT: The world's
ancient cities still contain

many surprises and treasures
hidden from view for centuries.

Now, with the latest
scanning technology,

I'm revealing the secrets of three of
the most fascinating cities on Earth.

Cairo, the gateway to ancient Egypt.

Istanbul, the crossroads
between Europe and Asia.

And in this programme, Athens,
the birthplace of democracy.

Today, Greater Athens is home
to almost four million people.

It's a city that has exploded with life
over the past century

and, as a result,
ancient sites and monuments

sit cheek by jowl with modern architecture
and urban renewal.

It's an intoxicating mix of ancient
and modern clashing together.

The temples of ancient Athens
dominate the city skyline,

but I'm also exploring its hidden secrets,

buried deep beneath the modern streets.

I thought I knew Athens,

but I've never been in a place
quite like this.

I'll be working with
our 3-D scanning team...

We're going to be scanning
the edges of the water

so we're going to take to the air.

...to reveal the secrets
of Athens' ancient past...

...and to explore
its brilliant golden age.

In which the citizens
of Athens created an idea

that we still cherish
over 2,500 years later.

Democracy.

I'll be exploring ancient silver mines...

What a world.

- Whoa!
- Whoa!

...and using virtual reality
to discover this amazing city

in a whole new way.

You wonder what they've been staring at
for the past 2,500 years.

Athens is a city with layer after layer
of history and mythology.

The ancients knew this place
as the City of the Gods.

Welcome to Invisible Athens.

The Acropolis - a sacred hill
in the centre of Athens.

5,000 years ago,
its cliffs offered protection

to Bronze Age settlers,

and in the centuries that followed,

the city grew up around it.

At the end of the sixth century BC,

a remarkable event took place here.

The people of Athens
overthrew a tyrant on this hillside

and started to create
the world's first democracy.

In the golden era that followed,
the Athenians built

the beautiful monuments
that sit here today.

I'm walking through the Propylaea,
the ancient gateway to the Acropolis.

It was designed to funnel your vision down

until it exploded out again

to reveal one of the most important
buildings in human history.

The Parthenon.

It was built to honour the goddess Athena,

and on first impressions, this beautiful
temple is a model of order and symmetry.

But when you look closer,
it becomes even more impressive.

And that's because there's barely
a straight vertical line on it.

Each of its 46 columns curves out

and then tapers almost imperceptibly
inwards as it rises.

This architectural trick
is what gives the Parthenon

its grace and power...

...and creates the illusion of a temple
always reaching for the heavens.

It's not just the beauty of this building
that strikes you.

It's the powerful message and purpose
that it was intended to convey.

It's civilisation versus barbarism,

with this building
and the city that it's at the centre of

as the beating heart of civilisation.

Sitting in the shadow of the Parthenon
is another, smaller temple.

It's often overlooked,
but it's no less significant,

and we're going to find out

why this is one of the most important
buildings of ancient Athens.

The Parthenon is
renowned for its symmetry,

but the same cannot be said
of its eccentric little brother

just across the way.

This is the Erechtheion today, but in
ancient times it was simply known as

"the building in which
the statue of Athena is".

But it's also the most asymmetrical
building in ancient Greece.

It's all different bits of architecture
that have sort of been higgledy-piggledy

smashed together
in all sorts of weird ways.

And so the question is, why did they
design a building to look like this?

Our 3-D scanners
are going to try to make sense

of this intriguing temple.

The team is led by architect Matt Shaw.

So, Matt, we've got
this uniquely asymmetrical building.

How are we going to tackle that
with the 3-D laser scanning?

Well, you have this complete clarity
over there with the Parthenon

and here, you're right, this complexity
and almost this confusion,

so the first thing for us to do
is just to map it really well,

to understand the geometry
of the Acropolis site itself,

and then we'll see exactly how the
Erechtheion is embedded into that site.

To reveal more about
the Erechtheion's setting,

Matt and his team are going to create
a 3-D model of the whole Acropolis.

Using thousands of aerial photographs

and a digital process
called photogrammetry,

they'll be trying to reveal
why the Athenians

designed the Erechtheion in this way.

And while they get to work,
I'm going to take a closer look.

The temple gets its name
from Erechtheus,

a mythical king of Athens.

He's said to have been killed here
by a thunderbolt thrown by Zeus,

king of the gods.

This confusing building
becomes even more confusing

when we realise that the ancient Greeks
purposefully left a hole in the roof

and a hole in the floor.

The mythical explanation for this

is this was the point where Zeus's
thunderbolt came from the sky

and killed Erechtheus.

But the connection with Greece's
ancient myths doesn't end there.

This temple also stands
over one of the crucial spots

in Athenian mythology -

the contest between the gods
to be the patron deity of the city.

Poseidon, the god of the sea,
and Athena, the goddess of wisdom,

had to pit their powers
against each other.

Poseidon supposedly struck
down into rocks

with his trident.

And he produced sea water
out of nowhere.

Not to be outdone, Athena planted
an olive tree near the same spot,

and the Athenian king
who was judging the competition

thought that an olive tree would be
more useful to the Athenians

than sea water,
and so declared her the victor.

From that moment on, Athena
would be the patron deity of Athens.

Today, an olive tree planted in 1917

marks the spot where
Athena's olive tree once stood.

Jutting out of another side
of the building is a porch

supported by columns in the form of
six maidens, known as the Caryatids.

This porch, too, was built
over more sacred royal ground.

We're so used to thinking
of the maidens acting as columns,

but actually they were guardians
of something far more important.

Deep beneath their feet,
deep down in that corner,

the grave, the mythical grave of the
founding king of Athens, Cecrops.

And so these maidens are doing far more
than just holding up the roof above them.

They're there in eternity,

pouring offerings
to this legendary hero.

These buildings on the Acropolis

have become enduring symbols of the city
that gave the world democracy.

But to Athenians, these were
sacred places for religious worship.

The political heart of their city
lies elsewhere.

Sitting just below the Acropolis
is a hill called the Pnyx,

and it's my favourite place in Athens.

Athenian citizens assembled
on this hillside to hear speeches

and cast their votes,
and if anywhere can lay claim to being

the world's first democratic
meeting place, then this is it.

But this wasn't democracy
as we know it.

Only Athenian men
were classed as citizens.

There were no votes for women,
nor for Athens' vast workforce of slaves.

But while we wouldn't recognise
Athenian democracy as democracy,

they also wouldn't recognise our system
as democracy,

because we don't each individually
get up and vote on every issue

as the Athenians did,
and it was on the Pnyx

that the very essence of their political
system was put into operation -

a direct vote by every citizen
on every issue.

Our scan team will be helping to reveal
the story of the ancient city

that lies beneath the surface
of modern Athens.

And now they're ready to show me
the first scans of the Acropolis.

I can't wait to see Athens
in all her glory,

and particularly the Acropolis.

Well, take a seat, and here we are.

You can take this kind of helicopter ride
around the site here.

MICHAEL: Yeah. And of course our eyes
are immediately attracted

towards the Parthenon,
the glory piece of the Acropolis.

And there it is - the eccentric
little brother of the Erechtheion,

that kind of weirdly designed building
sitting next door.

Let's take this model apart a little bit,
so we're going to...

...we're going to take
the Erechtheion away

and we'll just be left
with the foundations

and the marks on the ground,
I guess.

And here we are.

We take ourselves back in time
to before that building was even there.

What we're left with is this piece
of quite undulating terrain.

This is not a flat site here.

From the south side to the north side,

you can see there's this big drop in
terrain here - this is over three metres,

so the site is pretty constrained.

So it's got...
It's got difficulties of terrain.

What about also the pre-existing
sacred locations

and places that we know
were littered around here?

So the first of those

is this strange little hole in the ground,
actually, here.

Well, I mean the ancient sources
talk about it was Zeus's thunderbolt.

There are moments in time
and there are specific locations

that are really attached
to the ground itself.

Let's take this little sacred
moment on the ground

and let's bring in
some of the architecture.

So we've just popped the North Porch on
in a matter of seconds,

but we can see this hole in the ceiling
that is directly above,

and it frames this patch of ground
with this sacred hole in the middle of it.

It's how the Athenians
would have thought about

what they were building, that it
was visible to the all-seeing gods.

But there's something stopping them
extending the building.

(LAUGHS)

- It's the olive tree.
- It's the olive tree.

What are you going to do about that?

You can't move this olive tree,
supposedly Athena's olive tree.

- You're going to have to work around it.
- Yeah.

And I mean, we do this nowadays, right?
We have tree preservation orders.

- "You're not touching this."
- "This tree's not going anywhere." No.

If we take a sneaky peek
beyond Athena's olive tree,

there's another sacred site.

And so this is the Caryatid Porch,
isn't it,

that's sitting over the top,

we think, of the tomb of Cecrops.

Again, the building has to respect it

and it has to be commemorated in some way,
and marked.

It's layers of history
and identity and construction.

It's the constraints
of the landscape,

but it's also the constraints
of the sacred places

and objects they want to respect.

A patch of ground
touched by the gods,

an olive tree created by Athena,

and the tomb of Athens' founding king.

Three sacred spots
united around a central temple

housing shrines and relics to Athena
and many other gods.

So when you factor all of those things in,

this building becomes an ingenious
solution to the problem.

Looking at this building,
this little...this little gem here,

no longer is it
the sort of eccentric little brother,

it's actually the prime example

of what the Athenians could achieve.

(MERCHANTS SHOUT IN GREEK)

Today, modern Athens
is a vivid and colourful city

with a strong connection to the sea.

It's the bustling capital of a democracy

struggling to keep up with
its European neighbours.

At the time of the first democracy,

before the buildings
of the Acropolis rose up,

Athens also had to fight
to secure its place in the world.

In 490 BC, Athens was a Greek city state
surrounded by rivals.

Places like Aegina, Corinth

and the militaristic Sparta.

The greatest threats of all, however,
lay to the east,

where the Persian Empire
was growing in power and ambition.

But Athens had one great advantage
over many of its rivals.

The territory it controlled,
known as Attica,

was rich in natural resources.

And beneath these hills,
in the region of Laurion,

lay extensive seams of silver.

This was once an industrial landscape

teeming with slaves.

And the best way to explore
what this world was like

is to go inside one of the mines.

- Shall we go in?
- Yes.

- Watch your head.
- Watch my head, OK.

My guide is archaeologist
Professor Andreas Kapetanios.

He knows these mines
better than anyone.

When they started digging galleries...

Those are the galleries going back there?

Some of the galleries,
they are like octopus tentacles

and, er, they expanded all over
the underground world

because they tried to figure out
where to look for the ore.

- And that's where we're going?
- Yeah.

OK, well, I'm going to follow you, OK?

Because I certainly don't want to get lost
down here.

We have to crawl here.

Narrow and low.

- Michael, are you coming?
- I'm on my way...now.

These are actual tunnels

that they would have dug
in ancient times

- looking for the silver as they went?
- Looking for the ore

that the silver comes from.
If you come over here

you will see the deep, um,
tool marks.

The tool marks all around.

This gap here, this tunnel
is no more than half a metre in height.

I can't imagine how anyone
has the work space to move

and then actually work at
hacking away at the rock with tools.

I mean, it's incredibly tight.

Andreas, it feels like
we're heading downwards now.

You see, this is a kind of step,

- stepping downwards...
- Yeah.

And we find ourselves in a hole.

I'll try it head first, and hopefully
we won't be in too much trouble.

My God.

Andreas, this is probably
the narrowest piece.

ANDREAS: It's fine, it's fine.

- (LAUGHS) It's fine?
- Yeah!

This is officially insane.

I have to admit, though,
I'm kind of enjoying it.

(LAUGHS)

- ANDREAS: Are you through?
- I think I'm through.

This is incredible!

Are you coming?

It's sobering to think that the people
who dug these tunnels

2,500 years ago
were forced to work down here

for the benefit of the city of Athens.

ANDREAS: This was labour done
by tens of thousands of slaves.

Slaves were captured in wars
or they were bought in markets.

Slaves were very valuable -
valuable tools.

We can see pairs of adults
and children working together.

- Children?
- Yes, yes.

Can't help but feel for the people
who had to work hard

excavating down here in antiquity.

You're seeing the real underbelly,
the real Athens.

With all these tight tunnels
and narrow galleries, this is going to be

the hardest challenge
our scan team have faced yet.

- I do think we've got a while in here.
- Yeah.

I think we've got about six hours,
probably.

Really? How are you guys going to manage
getting all your scanning equipment

through some of these galleries?

I mean, it's teamwork, right? One of us
has got to creep through these holes

and the other one has got to pass
the equipment

and then we've got to creep again and
pass again and creep again and pass again.

I'm now incredibly curious
to see some of this silver ore

as they would have seen it
as they hewed it out of the rock.

I can show you a piece.

Wow!

Oh, it's sparkling.
It's beautiful, isn't it?

And this is what they were after.

But you need four tonnes of this
to produce two kilos of silver.

That's why they should move
mountains of this material.

These are the Silicon Valleys
of classical Athens.

Our scans reveal a labyrinth of tunnels
and chambers

over 100 metres long....

...cut by hand as the slaves
followed a thin seam of silver ore

into the hillside.

And above ground,
the scans also capture

the remains of the mine's
processing plants.

Here, the ore would have been washed,

then ground into tiny pebbles

before being heated in furnaces nearby

to coax out the precious silver.

This is just one
of at least 30 known silver mines

hidden under the hillsides of Laurion,

and the sources record that in the 480s BC

the Athenians hit on a new
and extremely rich vein of silver

which would prove a massive boost
to Athens' new democracy.

(CAR HORN TOOTS)

How to spend this lucky windfall

became a subject of fierce debate
amongst the citizens of the city.

Many wanted to cash in

and give every citizen
an equal share of the silver.

But one leading politician,
a heroic general called Themistocles,

put forward a powerful case

for investing the money
in a fleet of ships to defend the city.

The debate over what to do
with the Laurion silver

was decided by a democratic vote,

and as a result, the people poured
the money not into their own pockets,

but into the building of a fleet
and, henceforth, naval muscle and might

would be just as important a marker
of Athens as the democracy itself.

The naval muscle took the form
of warships known as triremes,

because they were powered
by three rows of oars.

At 40 metres long,
they were light and fast,

and fitted with bronze battering rams.

They were formidable weapons of war.

Here on the waterfronts,
we can peel back the layers of history

to show the strategic importance
of the Athenian fleet to the city

over several centuries. The scanning team
is already investigating.

So how are we going to
make the invisible visible this time?

Scanning on the inside,
relatively easy,

but we're not just doing the ruins,

we're actually doing
this whole apartment building here.

And then we're going to be scanning
the edges of the water here,

but getting a view into the water
is tricky for us.

So we're going to take to the air
for that,

so we want to see directly down
through that water

with a nice high sun,
and we're hoping that the structures

underneath the water are really
going to come to life for us there.

While the scan team gets to work outside,

I'm going to look inside with marine
archaeologist Dr Bjørn Lovén.

So, Bjørn, we can see the harbour
just there in front of us,

but where can we get a glimpse
of the ancient harbour?

Bjørn has investigated
the remains of ancient dry docks,

known as ship sheds,
tucked away in this basement.

What a magic, hidden,
invisible world underneath...

...underneath this apartment.

BJØRN: Yeah - we're so lucky
that this has been preserved.

Dry-dock ship sheds like this one
seem like a simple enough idea,

but they were vital to the success
of Athens' naval fleet.

BJØRN: The best way to show this,

- that if you stand on this column here...
- I'll get, OK, I'll get up on this one.

Then, er, over here to the other side.

So in this space between us
is one ship shed unit.

So if I go and stand...

If I'm here, I am where
the ancient trireme warship...?

Yeah, you are in the space.

So it really is like
a massive parking garage?

It is.

And we have to imagine that people
are pulling the ships up by hand?

Yeah. What we actually have here,

we have to imagine that right here
there would be a line of 70 men...

70 on this side, 70 on that side,
all pulling away?

Hauling away on big ropes that were
attached to the ram of the ship.

So they would want to
pull the ship up out of the water,

not just for repairs, I presume,
but also to dry it out?

Yeah, the drier and the more
well-maintained your ship is,

the faster it is in battle,

but the most important thing is that they

pulled the ships out of the sea
to protect it from the evil ship worm

that could actually destroy a ship
in a matter of months.

So it was to ensure
that it was a long-lasting,

perfectly functioning lethal weapon?

Yeah. You could say that the fleet was
the backbone of the Athenian democracy.

What's becoming much clearer to me now
is how, in the ancient world,

it was these industrial, commercial areas
down on the ports,

these ship sheds, where the engines and
motors of Athenian power and democracy

were housed and maintained

that was the ultimate symbol

of both the democratic
political system of Athens

and the power it projected
across the ancient world.

Our scans show how
the modern apartments

are built right on top of
the ancient ship sheds.

And using data gathered from our drone,

we've been able to map remains

that reveal how the ship sheds
extend under the modern road

and into today's harbour.

And our graphic shows how they once
stood all around this cove.

In 480 BC, thanks to
their wise investment,

the Athenian navy was 200 warships
strong,

just as Athens prepared to face
a mortal threat

from the most powerful empire
in the ancient world.

Down here in Piraeus, Athens' port,

a decisive sequence of events began.

An army of at least 200,000
Persian soldiers

was on its way to invade Athens
and crush its democracy.

And with the entire population at risk,

the Athenians had to decide
whether to stay and fight in the city

or to retreat by sea.

Themistocles knew the Athenians
could never hope to take on

the full force of the Persians on land,

and so he convinced them
to make an extraordinary decision -

to abandon Athens,
to abandon the land of Attica

and instead to put
all their hopes of survival

into the wooden walls of their ships.

And on that moment, that decision,
that democratic vote did history turn.

Women and children
were taken to safety

and every Athenian man of military age

took his place on a trireme

and prepared to face the Persians at sea.

The Athenians withdrew their fleet

just a short distance
across the water from the city

into a secluded bay
where they could plan their next move.

Here, they were joined by allies
from across Greece,

and in late September 480 BC,
they prepared to make a stand.

The battle that followed,
the Battle of Salamis,

was the moment the world's first democracy
faced its greatest threat.

It is one of the major turning points
of Western civilisation.

And until recently, barely any remains

dating from this moment
were thought to have survived.

But, in 2017, Professor Yannos Lolos
discovered new evidence

that helps us to understand what this bay
might have been like at the time.

YANNOS: On the eve
of the Battle of Salamis,

the united Greek fleet
was stationed in this bay

with over 300 triple-decker warships.

You've been investigating here
out in the bay.

What have you found here?

We have constructed the first underwater
geological map of the bay,

of the harbour, of Salamis.

This is the harbour of the city state
of Athens,

this is a fortified harbour,

including a long wall
with a round tower at each end.

There's no doubt about the crucial role
of this harbour

on the eve of the sea battle of Salamis.

We can imagine the Athenians,

who see from the heights
surrounding this bay

- their city in flames...
- It's just there behind us, isn't it?

I'm trying to imagine
the fear, the anger,

the desperation that the people
in this bay must have felt...

- Yes, yes,
- ...at that time.

Because Athens was no longer.

Using the new research,
our scan team has managed to fix

the coordinates of
the archaeological remains here.

Our graphic model of the harbour wall
and its defensive tower

shows how it extended 160 metres
into the bay.

And this is where the force
of over 300 Greek triremes gathered

to take on a Persian fleet
said to be three times as strong.

To help balance the odds,
the general, Themistocles,

managed to lure the Persians
into the narrow straits beyond the bay,

where their superior numbers
would count for nothing.

As the massive force funnelled
into the narrow stretch of water,

the Athenians and their allies pounced,

rammed into the enemy ships

and smashed the Persian fleet apart.

It was a stunning victory
for the world's first democracy.

But victory came at a high price
for Athens.

The people returned to a city in ruins.

Even their sacred buildings on the
Acropolis had been razed to the ground.

In the decades after the Athenians
defeated the Persians,

they did something
really quite extraordinary.

Instead of rebuilding their city,

they chose instead to leave it in ruins
as a memorial,

as they put it,
to the impiety of the barbarian.

And yet, while they would happily
leave their city in ruins,

the Athenians moved
as quickly as they could

to build something else entirely
to protect themselves in the future.

And that's what I'm trying to find here
in the streets of Athens today.

And I think...it's somewhere around here.

I've been told to take a left at the loos,

and now I'm looking
for some stairs downwards.

And here they are.

This you don't see every day
in a car park.

These are 2,500-year-old city walls.

The Themistoclean Walls of Athens.

You can still see the...

...the individual blocks neatly lined up
on top of one another,

and we've got here...
We've got one course, a second, a third,

a fourth, a fifth
disappearing into the floor,

and we're yet
nowhere near the foundations.

They must be even further down.

The story is that every Athenian was told
to drop whatever they were doing

and come and help build the walls,

and in the foundations,
they put anything they could find.

There's column drums in there,
sculptures, gravestones,

anything that would help this wall
rise up as quickly as possible.

Our scans and graphics
show that these walls,

concealed within the modern car park,

were part of a series of building projects

that would transform Athens.

First, the Athenians
enclosed their city,

then, almost ten kilometres away,
they fortified the port of Piraeus.

And then they linked the two

with a fortified corridor
that ran all the way

from the ports to the centre of Athens,

a system of long walls
almost 150 metres apart

and estimated to be 3.5 metres high.

With the completion of the Long Walls
connecting the port of Piraeus

to these walls guarding the city,

Athens effectively became
an island on the mainland.

No strictly land-based force
could really ever hope to conquer it.

And as a result, to many,
Athens seemed impregnable.

A bit narrow... Whoa!
...and into the water,

Let's see if we can get through this.

When the ancient Athenians

eventually did decide
to rebuild their city,

they wanted to do it bigger and better
than ever before,

and so they turned to
the very landscape around them,

because the land around Athens

is literally made of marble.

Although we're obviously driv...

- (CLUNK)
- (LAUGHS)

...just driving on, it's like
we're driving on a marble road.

We're driving on Penteli Mountain

and it was here
that the Athenians came to quarry.

The quarry face that dates from that time
is still here.

And archaeologist Alexandra Mari
is going to show me.

And what were your impressions
when you first saw it?

I was, er, amazed, actually,
by all these things which are here.

- This is it.
- Wow! This is the quarry.

- Isn't it nice?
- It's extraordinary.

It's huge! I mean,
it's massive, you can see

- the sheer walls they quarried off.
- The walls, yes, yes.

Can we get any sense of how much marble
was quarried out of this space?

Well, approximately 400,000 tonnes
of marble

were produced by this quarry -
the Quarry of the Cave, as it is called.

And you can see all the cut marks,
can't you,

of all the individual chisels
moving, moving...

ALEXANDRA: First of all, they had to
choose the right block,

without fissures and cracks,
and then they would start hammering,

continuous hammering until
they managed to split the block.

- But that's incredibly dangerous...
- Yes.

- ...and time-consuming and hard work.
- Very, very much, yes. Yes, yes, exactly.

What they had to do was, er,

to transport it to a special road
called Lithagogia,

meaning conveyance of stones.

And there's nothing left
of that road today?

- Well, yes, there is, actually.
- There is?

Just a little, a small part.

This was once the start of a long route

that ran from the quarry to the heart
of the city over 18 kilometres away.

I mean, it's still beautiful, isn't it,
over 2,500 years?

- I mean, it's like a sledge track.
- Yes, exactly.

It seems that, er,
they were using animal fat

in order to grease the flagstones
and reduce the friction.

And the danger that
if one block of marble got away,

it would just sweep down
the mountain?

And a little further down the hillside

is in fact one runaway block
from the quarry above.

But take a look at this view.
What do you think about it?

Hang on a sec, is this...?

This is a piece of a column.

- It's a column drum.
- Mm-hm.

So perhaps somebody did
take their eye off the job

and was looking at the view
and they missed their rope.

- After all.
- And it all went!

This weighed ten tonnes.

Can you imagine
having to go back up to the top

to all the workers who have been quarrying
this piece of stone

and go, "Sorry, guys,
we've got to start again"?

"It just broke," yeah.

A phenomenal sort of marker
to an incredible process.

Yes, exactly.

The marble that was quarried here

and transported all the way to the city
became the face of Athens' new identity -

that of a place
on the cusp of a golden age

of not just art and architecture,
but politics, philosophy, culture -

a golden age that still burns bright
in our human story.

Our 3-D model shows how the gleaming
marble from Mount Penteli

was used to create brand-new monuments
over the ruins of the Acropolis...

...the most prestigious of which were
the Parthenon, started in 447 BC...

...the Propylaea, a temple to Nike...

...and of course the Erechtheion...

...all completed
in one remarkable 40-year burst

of creativity and confidence

in the second half
of the fifth century BC.

Athens was now the most powerful city
in Greece,

and the Athenian Empire began to
extend its influence across the sea.

So, Costas, we have calm seas today,
good seas to be out on the boat?

Yes, it's very good weather.

This is Cape Sounion.

It's about 80 kilometres
south of Athens

and it's the southernmost tip of
the land of the Athenians, Attica.

For the Athenians
who'd been out across the Aegean

on trading ventures or military
expeditions,

the sight of this place
meant that they were finally home.

But something of a mystery
has grown up around Sounion.

Thanks to the Temple of Poseidon
that sits on the hill,

it was mostly known as a sacred site,

and until recently,
that's overshadowed the strategic role

it played in Athens' empire.

Now a team of archaeologists,
including Dr Kalliopi Baika,

are discovering how important
it really was.

There was a settlement
with a very important strategic role

and commercial value,

and here we're standing in front of
a very big, massive building, actually.

This is a corner, and the other part of
the corner you can see the other way.

So basically I'm standing
in the middle of what was once

- a wall going that way...
- Yes, a massive wall.

...out to sea.

They didn't build the building
half on the land and half in the sea,

- so something's changed?
- We have a relative sea-level change

of two metres and a half,

almost three metres,
from the fifth century BC.

So what you're telling me is that half of
the settlement that was here at Sounion

- is there in the water?
- Yes.

- And we can get in and explore that?
- Absolutely, yes, we can.

Sounion's crucial role in the defence
of the Athenian Empire

is now becoming clearer.

Sounion is the most sophisticated

small-scale naval base
in the Mediterranean.

Here, we have a strategic lookout post

that operates in a network of naval bases.

And that means, from here, a ship could
reach the message to Athens

that an enemy fleet is approaching
in only one hour.

The water is clear,

but I'm having trouble
finding the remains of the city.

Yes, the vertical lines,
the small structures from this way.

And, finally, here they are.

Massive sections of defensive wall
from the submerged city,

still recognisable after 2,500 years.

And one of the berths of the ancient
naval base cut into sheer rock.

And fine marble blocks from what must
have been impressive structures

in this strategically important town.

It's absolutely amazing down there,
as clear as day.

It must have been once upon a time
stretching down from the coastline,

now under the water behind me,
the remains of a massive wall.

As you come out from the coast,
the ancient blocks, they're a decent size,

but they get bigger and bigger
till the ones here -

must have been an enormous fortification
wall for the ancient town of Sounion.

It feels like a world frozen in time
down there.

Fortified naval bases like Sounion

helped Athens extend its empire
across Greece,

the Aegean and the coast of Asia Minor.

But its supremacy didn't go unchallenged.

From here on the hill above Sounion
you can look out

towards the Peloponnese,
home to their bitterest Greek rival -

Sparta.

In the second half
of the fifth century BC,

the two cities waged war on and off
across this territory for almost 30 years.

Athens relied mostly on its famous fleet
to fight its cause...

...while the citizens took refuge
behind their city walls.

But in 405 BC, the Spartans
finally lured Athens into

a disastrous sea battle...

...and then laid siege
to their weakened city.

Athens was forced to surrender
the following year.

The golden age of the world's first
democracy was coming to an end.

Its ideals and achievements, however,
would never be forgotten.

That was partly due to
the Athenians themselves,

who eulogised their golden age
in the centuries that followed,

but it was also partly thanks
to the Romans,

who came to control Athens
in the first century BC.

And over the next two centuries
Athens became

a kind of theme park cum finishing school
for the Roman elite.

In the second century AD,
the Emperor Hadrian

was one of Rome's most passionate admirers
of all things Greek.

Hadrian didn't just repair
bits of Athens,

he claimed the city for himself.

This is the Arch of Hadrian

and there still, just above the archway,
you can read a text,

it says simply,
"This is the city of Hadrian."

Hadrian was on a mission
to improve Athens

and he lavished the city with gifts -
a library, a gymnasium,

and something even more crucial to
the everyday life of the people.

And that's what brings me here, to
the site of the modern Olympic Village.

I'm going to explore
a feat of Roman engineering.

Which means going underground...again.

- Tim, how are we looking?
- It's good.

I'm just getting
the final preparations here.

But you can feel the...
You can feel the hot air coming out

from under there. I can't even see
the bottom, I've got no sense...

It's about 16 metres straight down.

Just absolutely straight burrowed,
down through...

This shaft leads down to
a 2nd-century AD Roman aqueduct,

where TV cameras have never been
allowed to film before.

Oh, gosh, it's narrow now.

Oh, I can hear the water.

(LAUGHS)

Here we come,
into the underground aqueduct.

There we are.

God, I've got not even room enough
for me to stand sideways.

Have I got my torch?

Get to start exploring.

There's the water right there,
this is extraordinary.

Oh, I'm stuck, I am actually stuck.
I'll go more on my side.

I can see the passageway
just opening up behind me

is just going dead on.

The water is...

It's cold, it's fresh,
it's got that mountain feel to it.

You can see it's doing its job,

bringing the water from the hills around
Athens right into the centre.

I'm just trying to imagine the lives

of the people who were actually
cutting this out of the sheer rock.

I mean, absolutely appalling conditions.

I'm wondering whether these...
I keep seeing these...

They're sort of a little shelf.

This was how they managed to see down here
what they were doing.

They had small oil lamps, like my torch,
I can put it here,

just giving them enough
of a flickering light

by which to hack away
at the solid rock in front of them.

(THEY LAUGH)

Can't actually now turn my head back.
There we go.

This tunnel took 15 years
to dig out of solid rock,

and runs for 20 kilometres.

It's an astonishing feat
of ancient engineering.

And I've asked aqueduct expert
Dr Shawna Leigh to shed some light on it.

So, Shawna, how did they go about

building such a project
so deep underground?

They would dig vertical shafts

something between 33 and 35 metres apart

and, um dig towards each other
and ideally meet each other.

What happens
if you don't meet the first time?

So, um, you have to do a little S-curve
to sort of get it together.

- Just like this one we've come through?
- Yes, exactly, right there.

And we're talking about an aqueduct

- of over 20 kilometres in length.
- Right.

How did they manage
to get that gradient so perfect?

Well, it's absolutely striking
because it's all based on gravity,

so if the slope is too steep,
the water will move too quickly

and basically tear apart the tunnel.

And if it's too shallow,
the water won't move.

And here it is,
still flowing beneath our feet...

- Absolutely.
- ...almost 2,000 years later.

It's amazing, isn't it?

Oh, and this section's even narrower!

The aqueduct's getting lower and lower,
I'm having to go

actually down on my knees

right into the water. Oh!

But the pay-off
is this extraordinary vaulted ceiling.

They have these unusual markings
from...frankly who knows when?

It's nice to see the sky again.

The scans reveal the aqueduct
in amazing detail.

We can see several of
those remarkable curves

where the workmen
almost missed each other.

The section we scanned
was just over 80 metres long

and over that distance, the water level
drops less than half a metre.

A gradient so well-engineered

that the aqueduct was used
until the middle of the 20th century.

And this is just one part
of a network of ancient aqueducts

that runs for almost 80 kilometres
beneath the city of Athens.

I've seen so much
of ancient Athens hidden

beneath the surface of the modern city,

but now I'm going to experience it
in virtual reality.

- OK.
- Jump on in.

Oh...can't wait to see
what you've got waiting.

Ah, wow!

So this is the Acropolis, of course.

That's the gods' view!

We're, like, flying over the top
of the city.

So, actually, we can dive on in
a little bit here

and go and have a real detailed view
of the Erechtheion.

And this is, I mean, the best doll's house
in the world.

- Check this out.
- Today you can just

walk into the building.

I can put myself inside it
and look at it from this side.

Wow.

So we're back now at a scale
that you'll be super familiar with, right?

- The world is the real scale,
- This is one to one, wow.

- And actually you are not allowed here...
- No.

...in the real world.

We're right down looking up
at the whole of the porch, aren't we?

From the hole.

Whoa!

- You've got us flying through the air.
- Yeah.

So now we can just drift around
the Erechtheion.

We've just been through the door.

Hang on a sec,
now we're going into a wall!

There's a wall, whoa, whoa!

Whoa, we just went through the wall.

- Why not, hey?
- (LAUGHS)

And here we are.

Oh, wow.

What a view.

You wonder what they've been
staring at for the past 2,500 years.

Just step up on there
and, er, give them a hand.

What, so if I try to...?

Hang on a sec.

Whoa!

Oh, that is a freaky experience.

That's worse than flying through
the virtual world

cos you're actually propelling yourself...

And I'm right... I'm right next to them!

It's like, "Yeah, you know what?

"Easy peasy, no worries."

Do you think you could hold that pose
for two-and-a-half millennia?

Well, with a view like this,
yeah, it's not so bad.

I think it definitely
would have compensations.

Looking out over Athens' glory
of the Parthenon,

it's creating this link that was
so important to the Athenians

between the landscape,
the past, the present, the future.

If there's a spot you put yourself in
in Athens

to understand
what it means to be Athenian,

this is it.

The Athenians smelted silver
from their mines

and voted to invest it in a naval fleet.

They built dry docks
to preserve their warships.

They surrounded their city and their
harbour with extraordinary walls.

And they gave their city a unique identity

using marble
carved from their own quarries.

This bold democracy left a legacy
that has never been forgotten.

It's all too easy when you come to Athens
to be overwhelmed

by the beauty of the buildings on the
Acropolis, the Parthenon, the Erechtheion,

but what's become clear to me
is that the hidden and invisible spaces

of the city are just as important -

those mines and aqueducts,
those quarries and ship sheds,

those are the spaces
in which Athens itself was forged,

its ideas and dreams made real,

and those are ideas and dreams
that still inspire us today.