Original subtitles

Narrator: ANGKOR WAT, CAMBODIA.

THE LARGEST RELIGIOUS MONUMENT EVER BUILT.

THE ANCIENT KHMER CIVILIZATION CONSTRUCTED

THIS MAGNIFICENT HINDU TEMPLE 900 YEARS AGO...

Hendrickson: WHEN YOU GET UP CLOSE AND YOU LOOK AT THE DETAIL,

IT IS TRULY AN ABSOLUTE MASTERPIECE.

Narrator: ...THE CROWNING GLORY

OF A ONCE-GREAT EMPIRE.

IT'S EXTRAORDINARY ON SO MANY LEVELS

THAT IT'S VERY DIFFICULT TO EVEN COMPREHEND.

Narrator: WHY WAS THIS GARGANTUAN TEMPLE BUILT

SEEMINGLY IN THE MIDDLE OF NOWHERE?

AND HOW IS IT STILL STANDING AFTER CENTURIES OF NEGLECT,

RAVAGED BY JUNGLE TREES AND MONSOON RAINS?

TO UNEARTH THE TRUTH, WE'LL EXPLORE

THE TEMPLE'S STRUCTURE STONE BY STONE.

WE'LL EXPOSE ITS HIDDEN CHAMBERS AND LOST TUNNELS

TO REVEAL THE ASTONISHING SECRETS

OF THE LONG-LOST CIVILIZATION

THAT BUILT THIS ANCIENT WONDER.

-- Captions by VITAC -- www.vitac.com

CAPTIONS PAID FOR BY DISCOVERY COMMUNICATIONS

ANGKOR WAT, THE LARGEST TEMPLE ON EARTH.

THIS MASSIVE STRUCTURE DOMINATES THE JUNGLE LANDSCAPE

OF NORTHERN CAMBODIA.

BUT FOR CENTURIES, ITS SANDSTONE TOWERS

AND CARVED WALKWAYS WERE LOST TO THE FOREST,

HIDDEN BENEATH AN IMPENETRABLE CANOPY OF TREES.

NOW ARCHEOLOGISTS INVESTIGATING ANGKOR WAT ARE REVEALING

ITS HIDDEN SECRETS.

WORKERS HAVE CLEARED THE TREES TO REVEAL

A TEMPLE COMPLEX COVERING OVER 500 ACRES,

AND THERE COULD BE MORE.

ARCHAEOLOGY TEAMS USE INNOVATIVE LASER TECHNOLOGY TO HUNT

FOR THE LONG-LOST CITY THEY BELIEVE

MUST ONCE HAVE SURROUNDED ANGKOR WAT.

OTHER EXPERTS SEARCH FOR CLUES INSIDE THE TEMPLE

TO SOLVE THE MYSTERIES OF HOW AND WHY IT WAS BUILT.

IT'S PERFECTION IN TERMS OF CARVING.

IT'S PERFECTION IN TERMS OF DIMENSIONS,

IN TERMS OF RHYTHM OF SPACES WITHIN THE TEMPLE.

THIS REQUIRED AN EXTRAORDINARY VISION.

Narrator: ANCIENT ARCHITECTS DESIGNED ANGKOR WAT TO INSPIRE

AWE AND WONDER.

A MAJESTIC STAIRCASE LED PILGRIMS

TO A MAGNIFICENT CENTRAL ATRIUM

WHERE THEY CAME FACE-TO-FACE WITH VISHNU,

A SUPREME BEING IN THE HINDU FAITH.

FIVE IMPOSING STONE TOWERS ROSE ABOVE THEIR HEADS,

SYMBOLIZING THE SACRED MOUNT MERU,

HOME OF THE GODS.

BUILT USING HALF A MILLION TONS OF STONE,

ANGKOR WAT IS A SPECTACULAR

RE-CREATION OF HEAVEN ON EARTH.

BUT WHY DID THE ANCIENT CAMBODIANS BUILD THIS TEMPLE

SO MUCH BIGGER THAN ANY OTHER?

SIMON WARRACK HAS SPENT DECADES INVESTIGATING ANGKOR WAT

AND ITS SURROUNDING TEMPLES.

HE BELIEVES THE ANSWER TO THIS MYSTERY LIES IN DECODING

THE INTRICATE CARVINGS

THAT ADORN THE TEMPLE WALLS.

WE'RE IN THE THIRD ENCLOSURE OF THE TEMPLE OF ANGKOR WAT,

AND IN THIS ENCLOSURE, WE HAVE MORE THAN HALF A MILE

OF CARVED BAS-RELIEFS.

Narrator: THE CARVINGS TELL THE STORY

OF THE ANCIENT CIVILIZATION WHO BUILT THE TEMPLE --

THE KHMER.

THEY DEPICT THE ARMY'S MILITARY VICTORIES,

AND THEY GIVE US AN IMAGE OF A GREAT RULER --

KING SURYAVARMAN II.

SO HERE WE ARE IN FRONT OF KING SURYAVARMAN II HIMSELF.

THIS IS THE FIRST PORTRAIT OF A KHMER KING

IN THE HISTORY OF KHMER ART.

HERE HE IS SITTING ON HIS THRONE LOOKING VERY REGAL,

SURROUNDED BY HIS COUNSELORS

AND HIS MINISTERS, SEVERAL HOLY MEN.

AND WONDERFUL UMBRELLAS TO SHIELD HIM FROM THE SUN,

FANS, FLY WHISKS.

ALL THE ACCOUTREMENTS OF ROYALTY ARE HERE.

Narrator: CRITICALLY, KING SURYAVARMAN WASN'T BORN TO RULE.

HE HAD SEIZED POWER FROM HIS GREAT UNCLE,

AND SIMON IS CONVINCED THAT

ANGKOR WAT'S HUGE SIZE WAS A GRAND POLITICAL STATEMENT

TO WIN OVER HIS NEW SUBJECTS.

CARVED HERE IS THE MESSAGE THAT THE KING WANTED

TO GET TO HIS PEOPLE.

IN A WAY, THIS IS THE CAMPAIGN AD FOR SURYAVARMAN II.

Narrator: SURYAVARMAN DIDN'T JUST WANT TO BE SEEN

AS A RIGHTFUL KING.

HE WANTED TO BE REVERED AS A GOD.

SO HE BUILT A TEMPLE WITH AN EXTRAORDINARY SECRET

THAT LINKS IT TO THE HEAVENS.

EACH YEAR AT THE SPRING EQUINOX,

THE SUN RISES DIRECTLY OVER THE CENTRAL TOWER.

A HOLE IN THE CAPSTONE FOCUSES

THE SUNLIGHT DOWN INTO THE TEMPLE.

IT SHINES THROUGH A HOLE IN THE FLOOR BELOW

AND DOWN A 90-FOOT SHAFT

TO A SECRET CHAMBER DEEP UNDERGROUND.

SOME EXPERTS BELIEVE THAT SURYAVARMAN

DESIGNED THIS SECRET VAULT TO HOLD HIS MORTAL REMAINS.

IF THEY'RE RIGHT, ANGKOR WAT IS NOT JUST A TEMPLE.

IT'S A SPIRITUAL MACHINE TO ELEVATE THE GOD KING

TO HIS RIGHTFUL HEAVENLY THRONE.

BUT THIS IDEA CREATES ANOTHER BIG MYSTERY.

IF ANGKOR WAT WAS DESIGNED TO BE SURYAVARMAN'S TOMB,

IT HAD TO BE CONSTRUCTED

AND DECORATED IN TIME FOR HIS DEATH.

Warrack: THE REIGN OF KING SURYAVARMAN II WAS 32 YEARS.

THAT'S A VERY SHORT TIME TO BUILD THE BIGGEST

STONE RELIGIOUS BUILDING IN THE WORLD.

Narrator: THE GREAT EUROPEAN CATHEDRALS BUILT IN THE SAME ERA

TOOK CENTURIES TO COMPLETE.

YET THEY'RE A FRACTION OF THE SIZE OF ANGKOR WAT.

SO HOW DID THE KHMER ENGINEERS BUILD THIS REMARKABLE TRIUMPH

IN SUCH A SHORT TIME?

SIMON THINKS THAT THE SOLUTION

COULD BE A VAST SUPPLY OF MANPOWER.

TO TEST HIS THEORY, HE VISITS ANOTHER KHMER TEMPLE --

PHNOM BAKHENG --

WHERE A TEAM OF STONEMASONS

ARE REBUILDING THE TEMPLE'S SOUTHWESTERN WALL.

SIMON EXPERIMENTS BY CHISELING A SANDSTONE BLOCK.

HE WANTS TO INVESTIGATE HOW LONG IT WOULD HAVE TAKEN THE KHMER

TO DO THE SAME JOB 900 YEARS AGO.

Warrack: ROUGHING OUT WITH A POINT CHISEL AND A BIG HAMMER

IS REALLY HARD WORK.

AND THAT WOULD HAVE BEEN DONE BY THE LESS-SKILLED TEAMS.

Narrator: TO MAKE SURE THE BLOCKS SAT FLUSH AGAINST EACH OTHER,

THEY HAD TO CHISEL AND THEN SAND THEM

UNTIL THEY WERE PERFECTLY SMOOTH.

THE MOST UNCOMFORTABLE THING ABOUT DOING THIS KIND OF WORK

IS, OF COURSE, THE HEAT AND THE DUST.

Narrator: SIMON'S AN EXPERT STONEMASON,

BUT IT STILL TAKES HIM OVER TWO HOURS

TO PREPARE THE BLOCK FOR THE TEMPLE WALL.

THIS HERE IS A RELATIVELY SMALL BLOCK.

THIS IS ONE YOU CAN ACTUALLY MOVE BY HAND.

THE BLOCKS IN ANGKOR ARE UP TO 10 TONS

AND WERE PLACED IN SITU AND THEN WORKED BY HAND.

THE SIZE OF THAT TASK IS VERY DIFFICULT

EVEN TO ACTUALLY IMAGINE.

Narrator: SIMON SUSPECTS

IT WOULD HAVE TAKEN A KHMER STONEMASON UP

TO EIGHT HOURS TO PREPARE EACH OF THE MASSIVE BLOCKS

USED TO BUILD ANGKOR WAT.

AND WITH 5 MILLION BLOCKS TO PREPARE,

SURYAVARMAN WOULD HAVE NEEDED THOUSANDS OF STONEMASONS

WORKING EVERY DAY

TO COMPLETE THE TEMPLE WITHIN HIS LIFETIME.

AND THIS WOULD HAVE BEEN JUST A FRACTION OF THE WORKFORCE.

SURYAVARMAN ALSO NEEDED THE MATERIALS TO BE QUARRIED

AND TRANSPORTED TO THE JUNGLE SITE.

Warrack: YOU CAN ESTIMATE BY DOING A SIMPLE CALCULATION

THAT THERE WAS BETWEEN 200

AND 300 BLOCKS PER DAY ARRIVING ON SITE.

AND THAT IS ALMOST IMPOSSIBLE TO CONCEIVE.

Narrator: ANGKOR WAT SITS IN THE MIDDLE OF THE JUNGLE.

THE NEAREST SANDSTONE IS IN THE KULEN HILLS

25 MILES TO THE EAST.

ARCHAEOLOGICAL RESEARCH HAS REVEALED THAT THE KHMER

CUT CANALS TO JOIN UP THE RIVERS

TO CREATE A TRANSPORT ROUTE DIRECT

TO THE BUILDING SITE.

THEY CRAFTED BAMBOO RAFTS TO SUPPORT THE SANDSTONE BLOCKS.

AND THE CURRENT EFFORTLESSLY CARRIED THEM TOWARDS ANGKOR WAT.

THIS SYSTEM PROVIDED A CONSTANT SUPPLY OF SANDSTONE

TO AN ARMY OF BUILDERS

WHO WORKED TIRELESSLY TO ERECT A TEMPLE.

WE CAN IMAGINE AN ALMOST SOLID STREAM OF STONE GOING

FROM THE QUARRY TO THE SITE

AT THE HEIGHT OF THE BUILDING PERIOD --

A SITE I WOULD LOVE TO HAVE BEEN ABLE TO SEE.

Narrator: TO BUILD A TEMPLE OF SUCH EPIC PROPORTIONS IN SO FEW YEARS

WOULD HAVE TAKEN HUNDREDS OF THOUSANDS OF WORKERS,

PERHAPS THE LARGEST CONSTRUCTION TASK FORCE

EVER ASSEMBLED IN THE PRE-INDUSTRIAL WORLD.

Warrack: THE SIZE OF THE TEAM MUST HAVE BEEN EXTRAORDINARY

AND REALLY VAST.

IT SHOWS A CAPACITY FOR ORGANIZATION,

WHICH IS CHARACTERISTIC OF A VERY,

VERY GREAT CIVILIZATION.

Narrator: THROUGH SHEER FORCE OF NUMBERS,

KING SURYAVARMAN ACHIEVED HIS EXTRAORDINARY VISION,

AND THE FINAL STONE OF ANGKOR WAT WAS IN PLACE

BEFORE HE DIED.

BUT THIS SURPRISING FACT PRESENTS ANOTHER MYSTERY.

IF SUCH A VAST WORKFORCE WAS NEEDED TO CONSTRUCT THE TEMPLE,

WHERE DID THEY ALL LIVE?

TODAY THE TEMPLE APPEARS TO SIT LIKE AN ISLAND

IN A SEA OF DENSE JUNGLE.

IS NEW TECHNOLOGY ABOUT TO REVEAL

ANGKOR WAT'S MOST CLOSELY GUARDED SECRET?

Narrator: TODAY TOURISTS MARVEL AT THE SPLENDOR OF ANGKOR WAT

AND ITS VAST MOAT.

DESIGNED TO GLORIFY THE RULE OF AN AMBITIOUS KING,

IT CONTAINS HUNDREDS OF GRAND COLUMNS,

AND ITS WALLS AND TOWERS ARE ADORNED

WITH THOUSANDS OF EXQUISITE CARVINGS.

BUT 900 YEARS AGO, IT WOULD HAVE LOOKED EVEN MORE MAGNIFICENT.

ITS ROOFS WERE BEAUTIFULLY GILDED.

EVERY GATE CROWNED WITH FINE, GOLD-COVERED CARVINGS.

AND THE CENTERPIECE OF IT ALL --

THE FIVE LOTUS TOWERS ENROBED IN GOLD,

REFLECTING THE SUNLIGHT,

SHINING LIKE BEACONS ACROSS THE PLAIN.

IT TOOK HUNDREDS OF THOUSANDS OF WORKERS

TO BUILD THIS LAVISH MONUMENT,

YET TODAY THERE'S NO SIGN OF A CITY AROUND THE TEMPLE.

SO WHERE DID THESE ORDINARY PEOPLE LIVE?

IT'S A MYSTERY BECAUSE THE JUNGLE HAS SWALLOWED UP

ALMOST ALL TRACE OF OUTLYING SETTLEMENTS.

ARCHAEOLOGIST JEAN-BAPTISTE CHEVANCE

HUNTS FOR THE REMAINS

OF THIS 900-YEAR-OLD JUNGLE ATLANTIS.

TODAY HE'S CHASING DOWN THE RESULTS OF A GROUNDBREAKING

MAPPING TECHNOLOGY CALLED LIDAR.

THE LASER BEAMS SCAN THE GROUND, COVERING EVERY INCH.

IT STRIPS AWAY ALL THE TREES AND BUSHES

TO REVEAL THE TRUE LANDSCAPE

BENEATH THE DENSE VEGETATION.

JEAN-BAPTISTE'S INVESTIGATIONS

HERE REVEAL SOMETHING ASTONISHING.

ANGKOR WAT AND ITS SQUARE MOAT APPEAR TO BE SURROUNDED

BY A CITY GRID OF ANCIENT ROADS AND BUILDINGS.

TODAY JEAN-BAPTISTE WANTS TO CHECK OUT

SOME OF THE FEATURES PICKED UP BY THE LASER SCANNING

TO SEE FIRSTHAND

IF THEY REALLY ARE THE REMAINS OF AN ANCIENT CITY.

THIS IS A PROCESS CALLED GROUND TRUTHING.

THEY FOLLOW THE GPS SIGNAL TREKKING DEEP INTO THE JUNGLE.

JEAN-BAPTISTE LOOKS OUT FOR HUMPS IN THE JUNGLE FLOOR.

THESE HUMPS COULD BE THE REMAINS OF THE RAISED PLATFORMS

THE KHMER BUILT THEIR HOMES ON.

THE TEAM TAKES A CLOSER LOOK, HUNTING FOR EVIDENCE

THAT THESE HUMPS WERE MAN-MADE.

AND THIS EXCITING DISCOVERY ISN'T A ONE-OFF.

GROUND TRUTHING HAS CONFIRMED THAT A GIANT CITY

ONCE SURROUNDED THE TEMPLE OF ANGKOR WAT.

HOUSES FILLED THE SPACES WITHIN THE GREAT MOAT.

HUNDREDS OF THOUSANDS MORE STRETCHED OUT BEYOND,

DENSELY COVERING THE LANDSCAPE.

THE KHMER CUT WIDE CANALS BETWEEN THESE CITY BLOCKS,

CREATING A COMPLEX TRANSPORT NETWORK.

THIS VAST METROPOLIS STRETCHED OVER 400 SQUARE MILES

AND WAS HOME TO THREE QUARTERS OF A MILLION PEOPLE.

ANGKOR WAT WASN'T JUST A TEMPLE.

IT WAS THE CENTER OF A VAST MEGA CITY,

ONE OF THE LARGEST IN THE WORLD.

BUT HOW COULD A CITY OF THIS SCALE THRIVE

IN THE MIDDLE OF THE JUNGLE?

WHAT WAS THE SECRET INGREDIENT

THAT BANKROLLED THE CITY OF ANGKOR AND KICK-STARTED

THE EXPANSION OF A KHMER EMPIRE?

Narrator: ANGKOR WAT WAS ONCE

THE BEATING HEART OF A JUNGLE METROPOLIS,

BUT THE KHMER RULERS WERE INTENT ON CREATING AN EMPIRE.

SIMON WARRACK EXPLORES THE ANCIENT COMMUNITIES

THAT STILL LIVE IN THE HILLS AROUND ANGKOR WAT.

HE'S SEARCHING FOR THE MYSTERIOUS MATERIAL

HE BELIEVES FUELED THE KHMER'S RISE TO GREATNESS.

Warrack: WE'VE JUST FOUND A BLACKSMITH CREATING A TOOL

WHICH IS PORTRAYED ON THE RELIEFS OF ANGKOR,

WHICH ARE 11th CENTURY.

THIS IS IDENTICAL.

SO HE'S MAKING THE SAME TOOLS HIS ANCESTOR MADE

1,000 YEARS AGO.

Narrator: THESE TOOLS ARE BEING FORGED FROM IRON,

A METAL THAT'S HARD TO FIND IN THIS PART OF THE WORLD.

IT'S A LOVELY PIECE OF WORK, AND IT'S EXTREMELY SHARP.

AND I WOULD ENJOY USING THIS.

Narrator: COULD IRON HAVE BEEN THE SECRET WEAPON

OF THE KHMER EMPIRE?

Warrack: IRON WOULD HAVE BEEN THE PERFECT MATERIAL

AT THAT TIME.

YOU CAN MAKE IT SHARP.

YOU CAN MAKE A THICK CHISEL TO KNOCK OFF THE BIG LUMPS

WHEN YOU'RE WORKING DOWN A LARGE BLOCK.

YOU CAN WORK IT INTO A VERY THIN POINT

SO THAT YOU CAN WORK THE VERY, VERY FINE DETAILS

THAT YOU SEE ON ANGKOR.

Narrator: IF THE KHMER HAD ACCESS TO VAST QUANTITIES OF IRON,

THEY COULD HAVE USED IT TO BOOST ALL ASPECTS OF THEIR CULTURE...

...FROM CONSTRUCTION TO AGRICULTURE

AND, MOST IMPORTANTLY, WARFARE.

IRON WEAPONS WOULD EXPLAIN HOW THE KHMER EMPIRE

SPREAD SO QUICKLY,

CONQUERING ALL OF SOUTHEAST ASIA IN JUST 22 YEARS.

THE MILITARY WAS AN EXTREMELY IMPORTANT FEATURE

AND ENABLED THEM TO EXPAND AND TO CREATE AN EMPIRE

THE SIZE OF THE ONE THAT THEY DID.

Narrator: A GLUT OF IRON WOULD HAVE TRANSFORMED THE KHMER

FROM A SIMPLE CIVILIZATION TO A MIGHTY EMPIRE.

BUT HOW CAN WE BE SURE THEY HAD ACCESS TO ENOUGH

OF THIS RARE MIRACLE MATERIAL?

ARCHAEOLOGISTS HAVE DISCOVERED A CRUCIAL CLUE

HIDDEN INSIDE THE SANDSTONE BLOCKS

THAT MAKE UP ANGKOR WAT.

THE KHMER DIDN'T USE MORTAR.

REMARKABLY, THEIR GRAND TEMPLE WAS HELD TOGETHER BY IRON.

CURIOUS HOLES IN THE STONEWORK REVEAL HOW.

THESE ARE THE SCARS LEFT BY LOOTERS

WHO CHISELED INTO THE STONE

TO EXTRACT IRON CLAMPS.

DESIGNED TO HOLD THE STONES TIGHTLY TOGETHER,

THEY WERE PLACED BETWEEN THE SANDSTONE BLOCKS.

THERE MUST HAVE BEEN THOUSANDS OF THEM.

BUT WHERE DID THE KHMER GET ALL THIS IRON FROM?

AND HOW COULD THEY AFFORD TO BURY SO MUCH OF IT

INSIDE A TEMPLE?

ASTONISHINGLY, THERE'S NO IRON ORE FOUND AROUND ANGKOR WAT.

THIS PRESENTS ANOTHER PUZZLE FOR EXPERTS TO SOLVE.

WE'RE ABOUT A KILOMETER AND A HALF SOUTH OF PHNOM DIKE,

WHICH LITERALLY TRANSLATES INTO "THE IRON MOUNTAIN,"

AND THIS AREA'S REALLY IMPORTANT BECAUSE

THERE'S A SERIES OF MOUNDS

THAT ARE COVERED IN SLAG,

WHICH WE THINK ARE IRON PRODUCTION SITES.

Narrator: ARCHAEOLOGIST MITCH HENDRICKSON

BELIEVES THE KHMER RELIED

ON THE SPECIALIST SKILLS OF A TRIBE KNOWN AS THE KUY

THAT LIVED 80 MILES FROM ANGKOR WAT.

HE WANTS TO INVESTIGATE THE MOUNDS

FOR SIGNS OF ANCIENT KUY IRONWORKS.

BUT FIRST, HE NEEDS SPIRITUAL PERMISSION.

Hendrickson: BEFORE WE ACTUALLY UNDERTAKE ANY EXCAVATION,

WE HAVE TO DO A SMALL CEREMONY.

THE LOCAL TRADITION IS IF YOU DON'T CLEAR IT WITH THE SPIRITS,

BAD OMENS AND THINGS CAN HAPPEN TO YOU

AND THE PEOPLE WHO OWN THE LAND.

SO IT'S JUST BEST TO MAKE EVERYONE HAPPY

FROM THE SPIRIT WORLD TO THE CULTURAL WORLD, REALLY.

Narrator: MITCH BELIEVES THAT THE KUY

WERE ONE OF THE FEW TRIBES

WITH THE RESOURCES AND KNOW-HOW

TO PRODUCE VAST QUANTITIES OF IRON.

BUT HOW DID THIS VALUABLE METAL END UP IN THE HANDS

OF THE EMPIRE-HUNGRY KHMER?

Hendrickson: THE RELATIONSHIP BETWEEN THE TWO CULTURES --

IT WAS ALMOST A FORM OF EXCHANGE.

WE DON'T KNOW EXACTLY 'CAUSE THERE'S NO WRITTEN RECORDS,

BUT WHAT WE'RE TRYING TO DO HERE

IS TO UNDERSTAND THE TRADE OF IRON

BETWEEN THE SOURCE AND THE CONSUMER.

Narrator: TO PROVE HIS THEORY, MITCH AND HIS TEAM

ARE WORKING HARD TRYING TO UNCOVER EVIDENCE

OF IRON PRODUCTION

DATING TO THE PEAK OF THE KHMER EMPIRE.

Hendrickson: THIS IS TRENCH TWO,

WHICH IS SITUATED ON TOP OF THE MOUND.

WE CHOSE THIS LOCATION FOR A COUPLE OF REASONS.

ONE OF WHICH WAS THE HOPE THAT WE GET THE REMAINS OF A FURNACE.

AND WHAT YOU CAN SEE HERE IS ACTUALLY THE REMAINS

OF THE OUTLINE OF ONE OF THESE FURNACES.

WHAT WE HAVE IS THE INTERIOR AND EXTERIOR GOING AROUND

IN THIS HORSESHOE SHAPE.

AND INSIDE IS WHERE THEY WOULD HAVE ACTUALLY MADE THE IRON.

THESE LONG CLAY TUBES, WHICH ARE CALLED TUYERES,

IS HOW AIR WOULD HAVE PASSED INTO THE FURNACE,

WHICH WOULD HAVE ENABLED THE REDUCTION PROCESS.

SO THIS IS VERY EXCITING 'CAUSE THIS IS THE FIRST TIME

THAT WE'VE SEEN THE SHAPE OF ONE

OF THESE IRON FURNACES DURING THE ANGKORIAN PERIOD.

Narrator: MITCH'S DISCOVERIES ARE PROOF THAT THE ANCIENT KUY

WERE SMELTING IRON ON A VAST SCALE.

THEY BUILT THEIR CHARCOAL FURNACES FROM LOCAL CLAY

AND USED HUGE BELLOWS TO FEED THEM WITH OXYGEN,

KEEPING THEM BURNING AT A CONSTANT 1,800 DEGREES.

THEY FILLED THE FURNACES WITH NUGGETS OF IRON ORE,

AND AFTER 15 HOURS,

BROKE THE FURNACE OPEN TO RETRIEVE LUMPS OF IRON.

MITCH EXPECTS THE OTHER MOUNDS IN THE AREA

TO BE FILLED WITH SIMILAR REMNANTS

OF THE KUY'S EXTENSIVE IRON INDUSTRY.

Hendrickson: THIS IS ONE OF 12 MOUNDS

IN THE IMMEDIATE VICINITY.

THERE ARE PROBABLY HUNDREDS OF DIFFERENT FURNACES

THAT WOULD HAVE OPERATED AT THIS SITE,

AND THERE WOULD HAVE BEEN HUNDREDS

AT EACH OF THE SITES NEARBY.

WE HAVE A MASSIVE EXPLOSION OF IRON PRODUCTION,

WHICH SEEMS TO CORRELATE AROUND THE TIME PERIOD OF

WHEN ANGKOR BEGINS TO ASSERT ITSELF IN THE LANDSCAPE.

Narrator: ACCESS TO IRON TRANSFORMED THE KHMER

INTO A MONUMENT-BUILDING, WAR-WAGING EMPIRE.

BY THE 13th CENTURY, THE WHOLE OF SOUTHEAST ASIA

WAS PAYING TRIBUTE TO THE KHMER KING.

ANGKOR WAT, WITH ITS SHEER SIZE AND GRANDEUR,

WAS THE ULTIMATE SYMBOL OF THE EMPIRE'S GREATNESS.

BUT THE ANCIENT KHMER FACED A MONUMENTAL CHALLENGE.

ANGKOR WAT SITS ON SOFT, SANDY SOIL,

SO TO KEEP THEIR PRIZED JEWEL STANDING,

THEY NEEDED AN ENGINEERING SOLUTION OF UNPRECEDENTED SCALE.

Narrator: ANGKOR WAT IS THE LARGEST

SINGLE RELIGIOUS STRUCTURE IN THE WORLD.

IT STANDS 213 FEET TALL,

CONTAINS OVER 5 MILLION SANDSTONE BLOCKS,

AND WEIGHS OVER HALF A MILLION TONS.

THIS EXTRAORDINARY EDIFICE DEFIES

ACCEPTED ENGINEERING WISDOM.

IT HAS NO CONVENTIONAL FOUNDATIONS.

YET DESPITE THIS,

ANGKOR WAT HAS OUTLIVED THE CIVILIZATION WHO BUILT IT.

SO WHAT STOPS THIS COLOSSAL STRUCTURE

FROM SINKING INTO THE SOFT JUNGLE FLOOR?

THE WEATHERED WALLS OF THE TEMPLE REVEAL ONE POSSIBLE CLUE.

WHERE THE BLOCKS OF SANDSTONE HAVE FALLEN AWAY,

A MYSTERIOUS DIFFERENT TYPE OF ROCK IS EXPOSED.

THIS REDDISH STONE IS FILLED WITH POCKETS OF AIR.

IT'S CALLED LATERITE.

COULD THIS STRANGE HONEYCOMB-LIKE ROCK

BE THE REASON ANGKOR WAT IS STILL STANDING TODAY?

ARCHAEOLOGISTS HAVE REVEALED THAT THE BASE OF THE TEMPLE

IS A MOUND OF COMPACTED EARTH

TOPPED WITH ROUGH BLOCKS OF LATERITE

AND A THIN LAYER OF SANDSTONE PAVING.

THE KHMER THEN USED HUGE LATERITE BLOCKS

TO BUILD THE INNER CORE OF THE TEMPLE...

...AND AGAIN COVERED IT WITH SANDSTONE,

THIS TIME CARVING AND POLISHING

THE FACADE TO HIDE THE JOINTS.

ALTHOUGH IT'S WELL HIDDEN,

ANGKOR WAT HAS A HEART OF SPONGE-LIKE LATERITE.

BUT IS IT THERE TO STOP THE TEMPLE FROM SINKING?

RESTORATION EXPERT GINEVRA BOATTO

IS HUNTING FOR CLUES

AT THIS KHMER TEMPLE NOT FAR FROM ANGKOR WAT.

AS RESTORERS DISMANTLE AND REBUILD IT,

THEY REVEAL HIDDEN SECRETS ABOUT CLEVER KHMER ENGINEERING.

GINEVRA'S TEAM IS CURRENTLY RESTORING THE BUILDING'S

MANY LAYERS OF LATERITE AND SANDSTONE.

IT'S A RARE OPPORTUNITY TO INVESTIGATE

WHY THE KHMER CHOSE

THIS STRANGE COMBINATION OF BUILDING MATERIALS.

THEY MUST REMOVE EVERY BLOCK OF STONE TO REPAIR THE TEMPLE.

IT'S PAINSTAKING WORK.

EACH BLOCK OF THE INNER LATERITE LAYER MUST BE RESTORED

BEFORE IT CAN BE LIFTED BACK INTO THE WALL.

SURPRISINGLY, IT SEEMS THAT WEIGHT IS NOT THE ANSWER.

LATERITE TURNS OUT TO BE JUST AS HEAVY AS SANDSTONE,

DESPITE ITS HONEYCOMB APPEARANCE.

BUT IF THE ANCIENT KHMER DIDN'T USE LATERITE TO PREVENT

ANGKOR WAT FROM SINKING,

WHY DID THEY USE IT?

KHMER STONEMASONS COULD QUICKLY CARVE LATERITE INTO THE BLOCKS

THEY NEEDED FOR THE INNER LAYER OF ANGKOR WAT.

GINEVRA HAS SOLVED THE MYSTERY OF ANGKOR WAT'S HONEYCOMB CORE,

BUT SHE'S STILL NO CLOSER TO UNDERSTANDING

WHY THE GREAT TEMPLE HASN'T SUNK

INTO THE SOFT, SANDY FLOOR.

ENGINEER PEOU HANG BELIEVES HE MAY HAVE THE ANSWER.

HE THINKS THE VAST MOAT THAT ENCIRCLES THE TEMPLE

HAS A CRUCIAL ROLE TO PLAY.

KHMER ENGINEERS DUG A VAST MOAT,

MEASURING OVER THREE MILES IN CIRCUMFERENCE

AND 650 FEET ACROSS.

HOW DID THIS GIANT BODY OF WATER SUPPORT THE TEMPLE?

PEOU BELIEVES THE DRY SAND UNDER ANGKOR WAT

SHOULDN'T BE ABLE TO SUPPORT THE TEMPLE.

BUT ADDING WATER GLUES THE GRAINS OF SAND TOGETHER,

MAKING THE SOFT GROUND AS HARD AS CONCRETE,

ABLE TO SUPPORT MILLIONS OF TONS OF WEIGHT.

BY DIGGING A MASSIVE MOAT AROUND THE TEMPLE,

THE KHMER ENGINEERS CREATED A VAST RESERVOIR ABLE

TO HOLD MILLIONS OF GALLONS OF RAINWATER

SO THAT WHEN THE RAIN STOPPED,

WATER IN THE MOAT SEEPED INTO THE SOIL,

PREVENTING THE TEMPLE FROM COLLAPSING.

THE KHMER USED THIS BRILLIANT TECHNIQUE TO SUPPORT MANY

OF THEIR TEMPLES.

INGENIOUS WATER ENGINEERING HAS KEPT THESE GIANT TEMPLES

UPRIGHT THROUGHOUT THE CENTURIES,

EVEN WITHOUT FOUNDATIONS.

ARCHAEOLOGISTS BELIEVE THIS PRECISE CONTROL OF WATER

MAY HAVE SPREAD THROUGH ALL ASPECTS OF ANGKORIAN LIFE

FROM FARMING TO TRANSPORT AND EVEN RELIGION.

SO HOW DID THEY DO IT IN A LAND HIT BY CRIPPLING DROUGHT

FOR SIX MONTHS OF THE YEAR?

Narrator: THE CIVILIZATION THAT BUILT ANGKOR WAT

MYSTERIOUSLY VANISHED 400 YEARS AGO.

HISTORIANS HAVE TO HUNT FOR CLUES TO THEIR LOST CULTURE

IN THE TEMPLES THEY LEFT BEHIND

AND THE SURROUNDING RITUAL LANDSCAPE.

SIMON WARRACK IS UPRIVER FROM ANGKOR WAT

SEARCHING FOR THE ORIGINS

OF THE KHMER'S NEAR-RELIGIOUS OBSESSION WITH WATER.

Warrack: WATER IS AT THE HEART OF THE INCREDIBLE SUCCESS

OF THE KHMER CIVILIZATION --

THE MANAGEMENT OF THE WATER

AND THEREFORE THE SACRED NATURE OF WATER.

AND THAT'S WHY UP HERE ON THE KULEN MOUNTAIN,

WE FIND A RIVER WHERE THE BED OF THE RIVER

HAS BEEN CARVED WITH HUNDREDS AND HUNDREDS OF LINGAS.

Narrator: SIMON BELIEVES THESE SACRED LINGA CARVINGS

ARE OLDER THAN THE TEMPLE OF ANGKOR WAT.

Warrack: LINGAS ARE A SYMBOL OF FERTILITY,

WHICH GAVE SPIRITUAL SIGNIFICANCE

AND LUCK TO THE WATER,

WHICH WOULD THEN GIVE GREATER BENEFIT

TO THE PEOPLE OF THE CITY OF ANGKOR,

WHICH WAS DEVELOPING IN THE LANDS BELOW.

Narrator: SIMON'S THEORY IS THAT THE KHMER CHOSE A LOWLAND SITE

FOR THEIR SHOWCASE TEMPLE

BECAUSE THIS VERY SPECIAL SOURCE OF WATER FLOWED INTO IT.

AND ARCHAEOLOGISTS HAVE DISCOVERED FURTHER CLUES

TO THE KHMER FIXATION WITH WATER

HIDDEN DEEP INSIDE THE TEMPLE ITSELF.

ANGKOR WAT IS A SHOWCASE OF WATER ENGINEERING.

THE ROOF TILES SLOPE STEEPLY DOWN

SO RAINWATER RUNS OFF QUICKLY.

AND THE SANDSTONE WALLS HIDE AN ELABORATE DRAINAGE SYSTEM.

DOZENS OF HOLES AND TUNNELS

CARVED RIGHT INTO THE FABRIC OF THE TEMPLE.

RAIN FALLING ON THE STATUE OF VISHNU

WAS TURNED INTO HOLY WATER,

THEN FLOWED OUTSIDE FOR WORSHIPPERS TO WASH WITH.

BUT WHY WAS WATER SO CENTRAL TO THE KHMER STATE OF MIND?

ENGINEER PEOU HANG BELIEVES A CLUE CAN BE FOUND

IN AN ANCIENT KHMER STYLE OF HOUSING

DESIGNED TO DEAL WITH FLOODS DURING THE MONSOON SEASON.

THE ANCIENT KHMER FACED AN INCREDIBLE CHALLENGE --

TO FEED THEIR GROWING POPULATION

IN THE FACE OF SUCH WILDLY VARIABLE WATER LEVELS.

BUT BY PLACING THE CONTROL OF WATER AT THE FOREFRONT

OF THEIR CIVILIZATION,

THEY WERE ABLE TO CREATE THE PERFECT CONDITIONS

FOR GROWING THEIR MOST IMPORTANT STAPLE CROP ALL YEAR ROUND.

TO GROW RICE, THE KHMER NEEDED AT LEAST TWO INCHES OF WATER

IN THEIR PADDY FIELDS AT ALL TIMES.

TO ACHIEVE IT, THEY DUG VAST RESERVOIRS.

THE LARGEST OF THESE IS CALLED THE WESTERN BARAY

AND IS STILL IN USE TODAY.

DURING THE MONSOON, THIS MIGHTY RESERVOIR FILLS WITH WATER.

AND IN PERIODS OF DROUGHT, FARMERS OPEN GIANT SLUICE GATES

TO DIVERT THE WATER TO THEIR FIELDS.

THE NETWORK OF CANALS IN USE TODAY

REPRESENTS JUST A SMALL FRACTION

OF THE KHMER'S INGENIOUS IRRIGATION SYSTEM.

JUST NORTH OF ANGKOR, THE KHMER DIVERTED THE PUOK RIVER

INTO THE SIEM REAP CANAL,

WHICH FED THE VAST BARAYS.

THEY DUG A NETWORK OF CANALS

AND IRRIGATION CHANNELS TO CARRY PEOPLE

AND GOODS ACROSS THE MEGA METROPOLIS

AND CRUCIALLY TO SUPPLY WATER TO THE PADDY FIELDS,

LEADING TO AN EXPLOSION IN RICE PRODUCTION.

MOST PARTS OF THE COUNTRY HAD JUST ONE ANNUAL HARVEST,

BUT THE INNOVATIVE FARMERS AROUND ANGKOR WAT

COULD LOOK FORWARD TO MULTIPLE CROPS.

ONCE AGAIN, THE KHMER HAD TAMED THE ELEMENTS

AND TURNED THE TYRANNY OF THE MONSOON

TO THEIR ADVANTAGE.

INGENIOUS ENGINEERING MEANT THEY COULD FEED THE VAST POPULATION

NEEDED TO SUPPORT THE EXPANSION OF THEIR EMPIRE.

FOR CENTURIES, THE KHMER EMPERORS

ENJOYED UNRIVALED POWER,

BUT NOTHING LASTS FOREVER.

600 YEARS AGO, THE TEMPLES APPEAR TO HAVE BEEN

SUDDENLY ABANDONED

AND THE CITY THAT SURROUNDED THEM LEFT TO RUIN.

WHAT WENT WRONG?

Narrator: THE GREAT KHMER KING SURYAVARMAN II BUILT

ANGKOR WAT AS A SYMBOL OF HIS GODLIKE STATUS.

WITH ITS MAGNIFICENT LOTUS TOWERS

AND CARVINGS OF HINDU GODDESSES,

THE TEMPLE WAS A RE-CREATION OF HEAVEN ON EARTH.

900 YEARS LATER, IT REMAINS THE SPIRITUAL CENTER OF CAMBODIA.

Warrack: THE TEMPLE WAS, WHEN IT WAS BUILT,

AND REMAINS TO THIS DAY,

ABSOLUTELY THE HEART OF THE KHMER PEOPLE.

EVERY CAMBODIAN ANYWHERE IN THE WORLD

WILL DREAM OF VISITING THIS PLACE ONCE IN THEIR LIFE.

Narrator: TODAY BUDDHIST MONKS USE THE TEMPLE AS A RETREAT.

THEY COME HERE TO WORSHIP AND MEDITATE.

BUT THE VAST CITY THAT ONCE SURROUNDED

ANGKOR WAT HAS VANISHED.

WHAT CAUSED THIS MIGHTY EMPIRE TO SUDDENLY COLLAPSE?

SIMON WARRACK IS ON THE SIEM REAP RIVER JUST NORTH OF ANGKOR

LOOKING FOR CLUES TO THE DOWNFALL OF THE EMPIRE.

HE BELIEVES AN ATTACK BY A FOREIGN POWER

IS THE MOST LIKELY ANSWER.

BUT HOW COULD THESE INVADERS HAVE OVERCOME

THE FEARSOME ANGKORIAN ARMY?

IF YOU IMAGINE AN EMPIRE THE SIZE OF THE ANCIENT ANGKORIANS,

WHICH STRETCHED ALL THE WAY ACROSS SOUTHEAST ASIA,

THERE MUST HAVE BEEN MORE FACTORS IN PLAY.

Narrator: SIMON SUSPECTS

THAT AN ENVIRONMENTAL CATASTROPHE COULD HAVE WEAKENED

THE RESOURCES OF THE KHMER ARMY.

TODAY HE'S SEARCHING FOR EVIDENCE TO PROVE HIS THEORY.

THIS BRIDGE HERE -- IT'S MADE OF LOTS OF PIECES OF THE TEMPLE.

WE CAN SEE PIECES OF A VAULT.

WE CAN SEE CARVINGS.

SO IT MUST BE FROM THE LATE ANGKORIAN PERIOD.

BUT THE CLUE TO WHAT HAPPENED IS NOT SO MUCH IN THE PIECES

OF THE SUPERSTRUCTURE BUT WHERE ITS FEET ARE.

Narrator: SIMON THINKS THE POSITION OF THIS BRIDGE

HOLDS THE KEY

TO THE MYSTERIOUS COLLAPSE OF THE KHMER EMPIRE.

THE FEET CLEARLY LIE ON THE BOTTOM OF THE RIVER,

AS IT WAS IN THE ANGKORIAN TIME.

THE BOTTOM OF THE RIVER TODAY IS WHERE I JUST CLIMBED UP FROM.

SO THERE'S BEEN A DRAMATIC CHANGE

BETWEEN THE LATE ANGKORIAN PERIOD AND TODAY.

Narrator: THE RIVERBED HAS DROPPED BY AROUND 15 FEET.

Warrack: THIS CLEARLY SHOWS THAT SOMETHING HAS FAILED.

IT COULD BE A CHANGE DUE TO THE EROSION OF THE RIVERS

OR FAILURE IN THE WATER SYSTEMS.

Narrator: THE SIEM REAP RIVER WAS A CRUCIAL SOURCE

OF WATER FOR IRRIGATION,

AND THE KHMER WENT TO GREAT LENGTHS TO MANAGE IT.

Warrack: THE WATER WAS HELD IN POSITION

BY THEIR DRAMATIC CONTROL OF THAT CITY.

SO THEY WERE HOLDING THINGS UP WITH SLUICES, WITH DAMS,

AND EVERYTHING WAS UNDER CONTROL.

Narrator: BUT OVER TIME, EROSION WORE AWAY THE RIVERBEDS,

AND THE WATER LEVELS DROPPED.

THE KHMER FARMERS STRUGGLED TO DIVERT THE PRECIOUS WATER

TO THEIR FIELDS.

THE FAILING IRRIGATION SYSTEM TRIGGERED FOOD SHORTAGES

AND WEAKENED THE KINGDOM.

THE KHMER WERE NO LONGER STRONG ENOUGH TO DEFEND THEMSELVES.

FINALLY, THE SIAMESE KINGDOM OF AUTAYA LAY SIEGE

TO ANGKOR IN 1431 AND BROUGHT DOWN THE CITY.

THE GREAT KHMER EMPIRE AND ITS MAGNIFICENT TEMPLES

WERE LOST TO THE JUNGLE.

TODAY, DESPITE THE COLLAPSE OF THE CITY SURROUNDING IT,

ANGKOR WAT REMAINS AT THE VERY HEART OF THIS NATION.

THIS TEMPLE IS ON THE NATIONAL FLAG.

IT'S ON THE MONEY.

IT'S THE MOST IMPORTANT SYMBOL TO THE CAMBODIAN PEOPLE.

Narrator: ANGKOR WAT IS A TESTAMENT

TO THE MIND-BLOWING ACHIEVEMENTS OF A GREAT CIVILIZATION

WHO'VE MASTERED THE ELEMENTS,

HARNESSED THE POWER OF THE MONSOON,

BUILT ON AN UNIMAGINABLE SCALE

WITH PHENOMENAL FEATS OF ENGINEERING,

AND ACQUIRED EXTRAORDINARY WEALTH,

LEAVING AS THEIR LEGACY A TRULY AWE-INSPIRING MONUMENT.