All language subtitles for Secrets.of.the.Underground.S01E08.American.Stonehenge.1080p.AMZN.WEB-DL.DD+2.0.H.264-playWEB_track3_[eng]

DEEP BENEATH
AMERICA'S MOST NOTORIOUS PRISON,

A RECENT DISCOVERY
IS REVEALING OLD RUMORS

OF A SECRET TUNNEL SYSTEM.

DO YOU THINK
THOSE ARE AIR POCKETS?

WAS ESCAPING ALCATRAZ
MORE PLAUSIBLE THAN WE THOUGHT?

I'M GOING TO SEE
WHERE IT GOES.

NEW GROUND-PENETRATING
RADAR TESTS COULD REVEAL

A SIDE OF THE ROCK
WE'VE NEVER SEEN.

THERE'S DEFINITELY
SOMETHIN' RIGHT HERE.

MEANWHILE, AT THE BOTTOM
OF LAKE MICHIGAN

LIES A MYSTERIOUS PATTERN
OF ANCIENT ROCKS.

COULD THIS BE
AN UNDERWATER STONEHENGE?

3-D PHOTOGRAMMETRY
COULD UNCOVER NEW CLUES

HIDDEN ON THE ROCKS
FOR MILLENNIA.

DO YOU SEE THAT?

HIDDEN JUST BELOW
THE EARTH'S SURFACE,

THERE ARE COUNTLESS
UNSOLVED MYSTERIES.

AND, TODAY, WE FINALLY HAVE
THE TOOLS TO UNLOCK THEM.

LOOK AT THAT!WHOA.

I THINK THIS IS IT.

I'M ROB NELSON,

A SCIENTIST USING
STATE-OF-THE-ART TECHNOLOGY

TO PEEL THE LID OFF
OUR PLANET'S HIDDEN DEPTHS.

THE MOMENT OF TRUTH
RIGHT HERE.

HOLY MOLY!

THESE ARE THE SECRETS
OF THE UNDERGROUND.

Captions by VITAC--
www.vitac.com

CAPTIONS PAID FOR BY
DISCOVERY COMMUNICATIONS

ALCATRAZ-- ONE OF THE WORLD'S
MOST NOTORIOUS PRISONS.

BUILT ON A 22-ACRE ISLAND

SURROUNDED BY THE FRIGID
SAN FRANCISCO BAY,

THIS ISOLATED FORTRESS
ONCE HOUSED AL CAPONE,

MACHINE GUN KELLY,

AND DOZENS OF AMERICA'S
WORST CRIMINALS.

ITS LOCATION AND DESIGN

MADE IT ALMOST IMPOSSIBLE
FOR INMATES TO ESCAPE.

BUT THAT DIDN'T STOP
SOME FROM TRYING.

OVER THE DECADES,

THERE WERE AT LEAST
14 SEPARATE ESCAPE ATTEMPTS

BY AT LEAST
36 DIFFERENT INMATES.

MANY HAD HEARD ABOUT
A LEGENDARY NETWORK OF TUNNELS

THAT WERE SUPPOSEDLY CONCEALED
BEHIND A CELLBLOCK WALL.

ONE OF THEM WAS JIM QUILLEN.

IN 1944, HE WAS WORKING
A DETAIL IN THE KITCHEN

WHEN HE DISCOVERED A CRAWL SPACE
THAT LED TO A BRICK WALL.

HE SPENT HOURS
TRYING TO BREAK THROUGH

BEFORE HE WAS BUSTED.

THE EXISTENCE OF THESE TUNNELS
HAS NEVER BEEN CONFIRMED.

BUT NEW HIGH-TECH RADAR SCANS
SUGGEST THERE COULD BE

HIDDEN SUBTERRANEAN
PASSAGEWAYS LEADING AWAY

FROM THE CELLBLOCK
UNDERNEATH THE PRISON REC YARD.

SO, WAS JIM QUILLEN
ONTO SOMETHING?

WHAT IS ON THE OTHER SIDE
OF THAT WALL?

TO FIND OUT,
I'M HEADING THERE MYSELF,

ARMED WITH STATE-OF-THE-ART
SCANNING TECHNOLOGY TO EXPLORE

THE HIDDEN UNDERBELLY
OF THE ROCK.

IN RECENT YEARS,
GROUND-PENETRATING RADAR,

OR GPR FOR SHORT,

HAS UNCOVERED SOME
INCREDIBLE LONG-BURIED SECRETS,

INCLUDING A MYSTERIOUS NETWORK

OF TUNNELS UNDER A NEARLY
2,000-YEAR-OLD MEXICAN PYRAMID

AND AN ANCIENT ROMAN
GLADIATOR SCHOOL IN AUSTRIA.

TODAY, I'M BETTING
GPR CAN HELP US

FIND ANY HIDDEN PASSAGEWAYS
OR TUNNELS

THAT COULD HAVE OFFERED
DESPERATE INMATES

A HOPE OF ESCAPE.

MY FIRST STOP
IS THE MAIN CELLBLOCK,

WHERE ANY ESCAPE PLAN
WOULD HAVE ORIGINATED.

MEETING ME THERE IS
ALCATRAZ HISTORIAN JOHN MARTINI.

HEY, ROB.
WELCOME TO ALCATRAZ.

YEAH.
THIS PLACE IS INTENSE.

YEAH.
AND COLD.

WANT TO GO INSIDE?

YEAH.
OKAY.

SINCE THE MID-19th CENTURY,

ALCATRAZ HAS BEEN
SYNONYMOUS WITH OUTLAWS.

DURING THE CIVIL WAR,
CONFEDERATE SYMPATHIZERS

AND CITIZENS ACCUSED OF TREASON
WERE HELD HERE.

AFTER THE SPANISH-AMERICAN WAR,

THE RISING INMATE POPULATION,

WHICH INCLUDED
MANY SPANISH SOLDIERS,

WAS TASKED WITH BUILDING
A LARGER CELL HOUSE--

THE ONE I'M IN RIGHT NOW.

THERE'S CELLBLOCKS
ON BOTH SIDES.

A TOTAL OF 336 CELLS.

WOW.THERE WASN'T A LOT TO LIKE.

BUT THEY DID LIKE THE FACT
THAT YOU HAD ONE-MAN CELLS,

SO YOU HAD PRIVACY.

YOU DIDN'T HAVE TO WORRY ABOUT
BEING ASSAULTED BY YOUR BUNKIE.

THE DOWNSIDE WAS,
YOU COULD SPEND

UP TO 23 HOURS A DAY
IN THESE CELLS.

WHOA.
WANT TO GO IN?

YEAH.

WOW.
THESE ROOMS ARE SO TINY.

ONE BED,
A PLACE TO WASH YOUR HANDS,

A PLACE TO USE THE TOILET.

IF I WAS IN A ROOM LIKE THIS,

AND I KNEW THAT I REALLY HAD
NO CHANCE OF GETTING OUT,

I WOULD BE TRYING TO THINK
OF A WAY OF ESCAPING.

ONE OF THE MOST NOTORIOUS
BREAKOUT ATTEMPTS

WAS IN MAY 1946,

WHEN SIX PRISONERS
STOLE WEAPONS AND KEYS

AND TOOK CONTROL
OF THIS CELL HOUSE.

IT WAS DUBBED
THE BATTLE OF ALCATRAZ.

THE BUILDING WAS
UNDER SIEGE FOR THREE DAYS.

IF YOU LOOK AT THE WALLS,
THOSE ARE ALL SCARS, SHRAPNEL,

BULLET RICOCHETS

THAT EMBEDDED THEMSELVES
IN THE CELOTEX WALLBOARD.

THE UPRISING
WAS SO WELL-EXECUTED

THAT THE WARDEN
HAD TO BRING IN THE MARINES

TO TAKE BACK THE PRISON.

ULTIMATELY, ALL THE OFFENDING
INMATES WERE CORRALLED.

THREE WERE KILLED
IN THE PROCESS.

AND TWO MORE
WERE LATER EXECUTED.

BUT THEIR FAILURE DIDN'T
EXTINGUISH THE PERSISTENT HOPE

THAT AN ESCAPE
FROM THE ROCK WAS POSSIBLE.

SHORTLY AFTER THIS CELLBLOCK
WAS BUILT,

RUMORS BEGAN SWIRLING
THAT THE INMATES

HAD ALSO CONSTRUCTED
A SECRET NETWORK OF PASSAGEWAYS

UNDER THE NEW BUILDING THAT
COULD CONNECT TO THE OUTSIDE,

LEADING MANY, LIKE JIM QUILLEN,

TO BELIEVE THEY COULD
ACTUALLY USE THEM TO ESCAPE

IF THEY COULD BE FOUND.

IN HIS HEAD, QUILLEN HAD
ONLY BEEN THAT FAR FROM FREEDOM.

AND THAT'S HOW DEEPLY SET

THE STORY
OF THE SPANISH TUNNELS WAS.

JOHN TELLS ME
ABOUT A LESSER-KNOWN SECTION

OF THE PRISON
THAT SOUNDS LIKE A FITTING PLACE

TO START SCANNING
THE WALLS FOR CLUES.

THERE'S ACTUALLY
A LEVEL BELOW US

USED
FOR SOLITARY CONFINEMENT.

SO RIGHT UNDERGROUND...YES.

...WHERE WE ARE RIGHT NOW...YES.

...THERE'S A ROOM, BASICALLY.

IT'S MORE THAN A ROOM.
IT'S KIND OF A LABYRINTH.

IS THERE A WAY TO GET DOWN
THERE AND ACCESS THAT

AND TAKE A LOOK AT IT
FOR MYSELF?

I CAN TAKE YOU DOWN THERE.LET'S DO IT.

OKAY.

JOINING ME
UNDER THE MAIN CELLBLOCK

IS GEOPHYSICIST STEFAN BURNS,

WHO IS AN EXPERT ON USING
GROUND-PENETRATING RADAR

TO IDENTIFY HIDDEN POCKETS
AND PASSAGEWAYS.

NEED HARD HATS.

FLASHLIGHT?

I'LL GO FIRST.OKAY.

THIS AREA WAS CALLED
THE SPANISH DUNGEONS.

THIS DARK, DANK BASEMENT

IS WHERE INMATES WHO VIOLATED
PRISON RULES WOUND UP.

TROUBLEMAKERS COULD BE KEPT HERE
IN SOLITARY CONFINEMENT

FOR UP TO 19 DAYS IN THE DARK

WITH NOTHING
BUT THEIR PRISON-ISSUE CLOTHING,

NOT EVEN A BLANKET.

SOME OF THE RUMORS
THAT WERE SPREADING AT THE TIME

WERE THAT THE SPANISH DUNGEON
LED TO SPANISH TUNNELS

AND THE ACCESS
WOULD BE THROUGH HERE.

YES.
ANYTHING THAT WAS BRICK

TO THESE GUYS SAID,
"OOH, SPANISH TUNNELS."

SO EVERY GUY
THAT DID TIME DOWN HERE,

WHEN HE GOT BACK UP TOP,

HE BLABBED AND GAVE RISE

TO THE STORIES
OF SPANISH TUNNELS.

THE QUESTION IS,

COULD THERE HAVE BEEN
MORE TO THESE RUMORS

THAN WISHFUL THINKING?

STEFAN AND I ARE GONNA TAKE
SOME OF THIS HIGH-TECH EQUIPMENT

AND LOOK SPECIFICALLY

AT THE WALLS
NEAR THE REC YARD

AND SEE
IF WE CAN SEE ANYTHING.

THE PRISON RECREATION YARD

IS WHERE SUBTERRANEAN AIR GAPS
WERE FIRST DETECTED

BY A TEAM OF SCIENTISTS IN 2013.

IF INMATES BURROWED
UNDERNEATH IT,

THEIR TRAIL
WOULD HAVE STARTED HERE.

THE REC YARD
IS BACK THAT WAY.

SO WE'RE GONNA BE
PARTICULARLY LOOKING

AT THE WALLS ON THIS SIDE.

READY TO GET
THIS POWERED UP?

YEP.

STEFAN AND I
ARE USING A TYPE OF GPR

THAT CAN PENETRATE MASONRY
AND BUILDING STRUCTURES.

BE ABLE TO SEE
THROUGH THE WALLS.

IT WILL TELL US
IF THERE ARE ANY CHANGES

IN DEPTH BEHIND THE BRICK

THAT COULD SIGNIFY
A TUNNEL OR PASSAGEWAY.

RIGHT UP HERE
LOOKS FAIRLY CLEAR.

NOTHIN' REALLY ANOMALOUS.

I'M GONNA MOVE DOWN.

OH, LOOK.
THERE YOU GO.

YOU CAN SEE SOMETHIN'
RIGHT THERE.

IN ONE SECTION OF THE WALL,
THE DATA SPIKES.

IT LOOKS LIKE WE COULD
BE ONTO SOMETHING.

DO YOU THINK
THOSE ARE AIR POCKETS?

WILL OUR RADAR POKE HOLES

IN THE ROCK'S
INVINCIBLE REPUTATION?

LOOKS LIKE A CRAWL SPACE
RIGHT IN THIS REGION RIGHT HERE.

AND LATER, I'LL TRAVEL
TO THE SHORES OF LAKE MICHIGAN

TO INVESTIGATE
A MYSTERIOUS PATTERN OF ROCKS

THAT SOME PEOPLE ARE CALLING
AMERICA'S UNDERWATER STONEHENGE.

DO YOU SEE THAT?

THERE'S DEFINITELY
SOMETHING THERE.

I'M IN THE INFAMOUS
ALCATRAZ PRISON ON THE HUNT

FOR A LEGENDARY SYSTEM
OF TUNNELS

THAT MAY HAVE OFFERED INMATES
THE HOPE OF ESCAPE.

DO YOU THINK THOSE ARE
AIR POCKETS DOWN THERE?

THAT COULD SIGNIFY AN AIR GAP
ON THE OTHER SIDE OF THE WALL.

THIS IS THE OUTSIDE WALL

OF THE NOTORIOUS
SPANISH DUNGEON,

A SUBTERRANEAN SECTION
OF THE PRISON

EVERY BIT AS FOREBODING
AS THE NAME IMPLIES.

FOR DECADES,
RUMORS PERSISTED AMONG INMATES

THAT ITS WALLS CONCEALED TUNNELS
THAT COULD BE USED TO ESCAPE.

AND I MAY HAVE JUST FOUND
NEW EVIDENCE TO PROVE IT.

LOOKS LIKE A CRAWL SPACE
RIGHT IN THIS REGION RIGHT HERE.

REALLY?
YEAH.

IN AN OLD STRUCTURE
LIKE THIS PRISON BASEMENT,

AN AIR GAP IN THE WALLS
COULD BE ONE OF MANY THINGS.

BUT I'VE GOT ANOTHER TOY
IN MY TOOL KIT

THAT MIGHT REVEAL
A BIT MORE INTEL.

I HAVE A THERMAL IMAGING CAMERA.

ANYTHING I POINT AT, IT'S GONNA
SHOW ME A HEAT SIGNATURE.

SO IF I POINT
OVER HERE AT STEFAN,

YOU CAN SEE HIS NOSE IS COLDER
THAN THE REST OF HIS FACE.

THAT MAKES SENSE.
IT'S STICKING OUT.

THIS IS THE SAME SORT OF CAMERA
THAT INSPECTORS WOULD USE

TO COME IN
AND LOOK AT BUILDINGS.

I'M GONNA USE THE CAMERA
TO TRY TO LOOK AROUND

AND SEE WHAT'S GOING ON
BEHIND THE BRICK.

EVERYTHING'S PRETTY DARK.

THE THERMAL CAMERA
WILL SHOW THESE SOURCES

IN VARYING SHADES OF COLOR.

WHITE, RED, AND YELLOW
EQUAL WARM AIR.

BLUE, GREEN, AND BLACK
MEAN COOLER AIR.

ON A FRIGID NIGHT LIKE TONIGHT,

ANY TUNNEL OR PASSAGEWAY
BEHIND THESE WALLS

WILL REGISTER
ON THE COLDER SIDE.

WHAT'S BACK HERE?

AS I WORK MY WAY
ALONG THE DUNGEON'S OUTER WALL,

IT BECOMES CLEAR THERE
IS SOMETHING UNUSUAL BEHIND IT.

IT IS A LITTLE BIT COOLER
BACK HERE.

BUT THE THERMAL READINGS
STILL AREN'T GIVING ME

ENOUGH DETAIL
TO DETERMINE WHAT IT IS.

THEN, IN THE DEEPEST
RECESS OF THE DUNGEON...

HOLD ON A SECOND.

I COME ACROSS
SOMETHING CURIOUS...

HOLY MOLY.

...AN OPENING IN THE FLOOR.

OH, MY GOSH.
LOOK AT THAT.

YOU CAN JUST FEEL THE COLD AIR
PUMPIN' OUT OF THERE.

I'M GOING TO SEE WHERE IT GOES.

LOOKS LIKE A 7-, 8-FOOT DROP.

IMMEDIATELY, I BEGIN WONDERING

WHETHER THIS TUNNEL
MIGHT CONNECT TO THE SPACES

WE FOUND BEHIND THE WALL.

BUT THERE DOESN'T SEEM
TO BE ANY OBVIOUS LINK.

IF YOU LISTEN
REALLY CAREFULLY...

YOU CAN HEAR THE OCEAN.

YOU CAN FEEL THE COLD AIR
RUSHING IN HERE.

I HAVE MY GoPro
RIGHT AT THE MOMENT.

I'M GONNA JUST GET A LITTLE BIT
OF A PEEK WHAT'S GOIN' ON.

HOLY SMOKES.

YOU CAN SEE
THAT THIS TUNNEL KEEPS GOING.

THIS IS EXACTLY

HOW I WOULD PICTURE
MYSELF ESCAPING FROM ALCATRAZ.

BUT I WOULDN'T GET VERY FAR

BECAUSE IT TURNS OUT
THIS IS A KNOWN SEWER TUNNEL

BLOCKED AT THE OTHER END
BY AN IMPENETRABLE METAL GRATE.

ANY PRISONER TRYING TO BREAK OUT
THROUGH HERE

WOULD HAVE FOUND HIMSELF TRAPPED
BEHIND ANOTHER SET OF BARS.

SO, AS MUCH AS I LOVE CRAWLING
DOWN PRISON SEWER PIPES,

I NEED TO STAY FOCUSED
ON THE NEW LEAD

REVEALED BY OUR GPR--

THE AIR POCKETS BEHIND
THE OUTSIDE WALL OF THE DUNGEON.

RIGHT NEXT DOOR TO IT
IS THE PRISON RECREATION YARD,

WHERE ANOTHER STRANGE SET
OF ANOMALIES

WERE RECENTLY DISCOVERED
BY A TEAM OF SCIENTISTS

FROM TEXAS A&M UNIVERSITY.

THEIR GROUND-PENETRATING
RADAR SCANS

REVEALED A SPRAWLING SET
OF ANOMALIES

DIRECTLY ADJACENT
TO THE MAIN CELLBLOCK.

COULD THOSE ACTUALLY BE TUNNELS
THAT CONNECT TO THE GAPS

WE FOUND
BEHIND THE DUNGEON WALL?

I NEED TO INVESTIGATE
THE REC YARD MYSELF

TO GET A CLOSER LOOK.

REC YARD RIGHT OVER THERE.

THE NEXT MORNING,
STEFAN AND I RETURN TO THE ROCK

WITH A DIFFERENT KIND
OF GPR DEVICE.

SIMILAR TO THE WALL DEVICE
WE USED YESTERDAY,

THIS GPR WORKS BY FIRING
MICROWAVES INTO THE GROUND.

THESE ARE POWERFUL ENOUGH
TO PENETRATE CONCRETE.

BUT ANYTHING BURIED
WILL BOUNCE THE WAVES

BACK TO A RECEIVER
ON THE MACHINE--

KIND OF THE WAY
AN ULTRASOUND WORKS.

GPR DOES ALL THE WORK
FOR YOU.

YOU JUST GOT TO BE
ABLE TO INTERPRET IT.

ALL RIGHT.
LET'S DO THIS.

GO AHEAD, WALK WITH IT
AT A NICE, EVEN PACE.

EACH STEP YOU'RE TAKING,

IT'S SHOOTING OUT
HUNDREDS OF DATA POINTS

AND THEN PLOTTING THEM
ON THIS DISPLAY.

IF THESE SECRET SPANISH TUNNELS
DO EXIST,

WE WILL SEE EVIDENCE
APPEAR CLEARLY ON THE SCREEN.

THAT'S PROBABLY THE BOTTOM
OF THE CONCRETE

THAT WE'RE GETTING RIGHT THERE,
'CAUSE IT'S FAIRLY HIGH UP.

THE GPR IS NOT REVEALING

MUCH OF ANYTHING
IN MOST OF THE YARD.

BUT LOOK AT THIS.

BUT THEN...

YEAH.

AGAIN AND AGAIN,
WE GO OVER THE AREA.

AND EACH TIME,
THE READINGS SPIKE.

WOW.

THERE'S DEFINITELY
SOMETHIN' RIGHT HERE.

COULD THIS BE THE SMOKING GUN

THAT PROVES THE LEGEND
OF THE SPANISH TUNNELS?

IF IT IS, MAYBE THE ROCK

WASN'T QUITE AS IMPREGNABLE
AS WE THOUGHT.

I'M IN THE REC YARD
OF THE INFAMOUS ALCATRAZ PRISON

LOOKING FOR EVIDENCE

OF A LEGENDARY SYSTEM
OF UNDERGROUND TUNNELS.

AND OUR GROUND-PENETRATING RADAR

HAS JUST UNCOVERED
AN INTRIGUING ANOMALY.

THERE'S DEFINITELY
SOMETHIN' RIGHT HERE.

AN AIR GAP OR A VOID
UNDER THE SURFACE.

RIGHT NOW, IT LOOKS LIKE
WE'RE LOOKING AT AN ARCH

THAT'S 18 FEET LONG,

AND THE BOTTOM OF IT
IS ROUGHLY 51 INCHES,

SO ABOUT 4 FEET

AND GOIN' ALL THE WAY
UP HERE TO THE TOP

ROUGHLY ABOUT-- WHAT IS
THAT-- 6 INCHES. YEAH.

THE QUESTION IS,
DOES THIS OPENING

CONNECT TO THE MAIN CELLBLOCK,

WHERE WE FOUND EVIDENCE
OF AIR POCKETS

BEHIND THE ADJOINING WALL?

WE GOT A PERFECT LINE
GOIN' RIGHT TO THAT CELLBLOCK.

ALL OF THESE ANOMALIES
THAT WE'RE FINDING

APPEAR TO BE
ABOUT 2 FEET UNDERGROUND.

THEY DON'T APPEAR
TO BE SOMETHING

THAT IS REALLY NATURAL.

THEY APPEAR TO BE MAN-MADE.

IT LOOKS LIKE
IT COULD BE A TUNNEL

HEADING RIGHT TOWARDS
THE MAIN CELLBLOCK.

COMPILING THE DATA
GATHERED ACROSS THE REC YARD,

WE'RE ABLE TO PEEL BACK
THE LAYERS UNDERGROUND

AND GET A MORE COMPLETE PICTURE
OF THESE ANOMALIES.

IT APPEARS
AS IF THE HOLLOW POCKETS

RUNNING THROUGH THE REC YARD
COULD CONNECT DIRECTLY

TO THE GAPS WE FOUND
BEHIND THE PRISON WALL,

GIVING US A POTENTIAL PATH

DIRECTLY FROM
THE SPANISH DUNGEON

OUT TOWARD THE OCEAN.

I CAME TO ALCATRAZ
VERY SKEPTICAL

THAT THERE COULD BE
SOME ELABORATE SYSTEM OF TUNNELS

STILL HIDDEN UNDER THE PRISON.

BUT GROUND-PENETRATING RADAR

IS NOW ALLOWING US
TO SEE ALL SORTS OF THINGS

WE NEVER COULD BEFORE.

AND BETWEEN THE SCAN OF THE YARD

AND THE LARGE ANOMALY
DETECTED BEHIND THE WALL,

I'M STARTING TO THINK
THERE MAY BE SOME TRUTH

TO THOSE LONG-HELD RUMORS
AFTER ALL.

BUT AS EXCITING AS THESE RESULTS
ARE, THEY AREN'T CONCLUSIVE.

WE NOW KNOW THERE ARE AIR GAPS
UNDER THE REC YARD

AND BEHIND THE CELLBLOCK WALL.

BUT THE GPR DATA
DIDN'T GIVE US ENOUGH DETAIL

TO DECIPHER
THEIR SHAPE AND SIZE.

SO I'VE GOT TO FIND
SOME OTHER WAY

AT PEERING UNDERNEATH ALCATRAZ

TO DETERMINE
WHETHER THE ANOMALIES

WE'RE SEEING IN THE DATA
ARE ACTUALLY TUNNELS.

WHILE DIGGING
FOR NEW RESEARCH ABOUT ALCATRAZ,

I CAME ACROSS ONE
OF THE LEADING ARCHAEOLOGISTS

IN THE BAY AREA, PETER GAVETTE.

PETER HAS BEEN USING
CUTTING-EDGE TECHNOLOGY

TO CREATE HIGH-TECH
DIGITAL MAPS OF THE ROCK.

THESE BRAND-NEW MAPS
CAN DISSECT THE COMPLEX LAYERS

OF HISTORY CONSTRUCTED ON
AND UNDERNEATH THE ISLAND

IN WAYS WE NEVER COULD BEFORE.

THIS IS EXACTLY WHAT
I'VE BEEN LOOKING FOR.

AND IT COULD BE THE FINAL PIECE
I NEED TO COMPLETE THIS PUZZLE.

LET'S SEE.

SO, WHAT WE'VE BEEN DOING
IS DIGITIZING THE MAPS.

AND THAT WAY, WE'RE ABLE
TO OVERLAY ALL OF THEM

ON TOP OF EACH OTHER
TO SEE WHAT HAPPENS

THROUGHOUT
THE LAYERS OF HISTORY.

THE MAIN CELLBLOCK, THE RUMORED
SITE OF THE SPANISH TUNNELS,

WAS BUILT BY SPANISH PRISONERS
IN THE EARLY 20th CENTURY.

BUT PETER THINKS THE KEY
TO UNDERSTANDING THE ANOMALIES

WE'VE FOUND IS TO LOOK BACK

AT THE EARLIER HISTORY
OF THE ISLAND

BEFORE THE PRISON EVEN EXISTED.

BEFORE ALCATRAZ
WAS A FEDERAL PENITENTIARY,

IT WAS A MILITARY FORTIFICATION
PROTECTING THE BAY.

HE TELLS ME
THAT THESE FORTIFICATIONS

WERE BUILT AROUND 1860

WITH THE CIVIL WAR
LOOMING ON THE HORIZON.

SO, THIS IS ALCATRAZ
AS IT IS TODAY.

PETER HAS BEEN USING
OLD SURVEYING DATA TO CREATE

A WORKING MODEL
THAT ISN'T JUST 3-D--

IT'S 4-D, MEANING WE CAN MOVE
NOT JUST THROUGH SPACE,

BUT THROUGH TIME.

TO ACHIEVE THIS,
HE FIRST HAS TO LINE UP

THE HISTORICAL MAPS WITH PRECISE
GPS IMAGES OF THE ISLAND.

THEN, HE DIGITIZES THE CONTOUR
LINES THAT SHOW ELEVATION.

THOSE EACH HAVE
AN ASSIGNED VALUE.

AND WHEN WE ASSIGN
THAT VALUE INTO THIS PROGRAM,

WE CAN THEN CREATE
A 3-D IMAGE.

OH, AWESOME.SO THEN WE GET A VIEW OF--

OF THE ISLAND
AS IT LOOKED IN 1867.

SO, WHAT WE CAN DO
IS DRAPE OVER

THE CURRENT BUILDINGS
AND TOPOGRAPHY.

OH, WOW.

FROM HERE, WE CAN LOOK
AT ALCATRAZ

AND HOW IT'S CHANGED.

THIS DIGITAL MODEL
IS STILL A WORK IN PROGRESS

AS NEW DATA CONTINUES TO BE
GATHERED ACROSS THE ISLAND.

BUT I'M HOPING IT CAN SHED LIGHT

ON THOSE ANOMALIES
WE FOUND IN THE DUNGEON

AND UNDER THE REC YARD.

COULD THEY REALLY BE REMNANTS
OF A LEGENDARY ESCAPE ROUTE?

YEAH, ZOOM IN THERE
A LITTLE BIT.

IN THIS AREA
UNDERNEATH THE REC YARD,

WE WERE GETTING A LOT
OF ANOMALIES GOING THIS WAY.

WHAT'S GOIN' ON?

LIKE, ARE THEY
SOME SORT OF TUNNELS?

CYCLING THROUGH DATA SETS

FROM DIFFERENT DECADES,
WE UNCOVER A LAYER

FROM THE MID-19th CENTURY
WITH MARKINGS

THAT BEAR A STRIKING RESEMBLANCE
TO THE AIR GAPS

I FOUND UNDER THE REC YARD.

WHAT IS THAT
WE'RE LOOKING AT RIGHT HERE?

THESE ARE
EARTHEN FORTIFICATIONS

THAT COVER BRICK STRUCTURES.

THAT STRUCTURE THERE PROVIDED
MILITARY PERSONNEL COVER

FROM FIRE
COMING FROM THE OCEAN.

SO WHAT WE'RE SEEING RIGHT HERE
UNDERNEATH THE REC YARD

IS NOT TUNNELS,
BUT CIVIL WAR FORTIFICATIONS.

RIGHT.

WOW.

AND JUST LIKE THAT,

THE TUNNELS ARE RELEGATED
TO MYTH ONCE AGAIN.

THE DATA FROM THE 4-D MODEL

APPEARS TO SUGGEST THE ANOMALIES
WE DETECTED UNDER THE REC YARD

WERE NOT ESCAPE TUNNELS.

INSTEAD, THEY WERE
MOST LIKELY GAPS

BETWEEN CIVIL WAR ERA
FORTIFICATIONS

FILLED OVER DURING CONSTRUCTION
OF THE PRISON REC YARD.

THOUGH I WAS SKEPTICAL AT FIRST,

OUR FINDINGS GOT ME EXCITED

THAT MAYBE THE INMATES
OF ALCATRAZ

REALLY DID KNOW
SOMETHING WE DON'T,

THAT THEY HAD BUILT
A SECRET NETWORK

OF ESCAPE TUNNELS
THAT OFFERED HOPE

FOR AN OTHERWISE
HELPLESS EXISTENCE.

BUT IT APPEARS THERE WAS NO WAY
OUT UNDERGROUND AFTER ALL.

SO THAT MUST BE
WHY THE ONLY PRISONERS

EVER TO ESCAPE FROM THE ROCK
WENT UP INSTEAD OF DOWN.

IN 1962, THREE INMATES
DUG THROUGH THEIR CELL WALLS

WITH SHARPENED SPOONS

AND REACHED A VENTILATION SHAFT
UP TO THE ROOF,

WHERE THEY SLID DOWN A VENT PIPE
50 FEET TO THE GROUND.

THEY THEN MADE
THEIR WAY TO THE BAY,

WHERE THEY SET SAIL
ON A MAKESHIFT RAFT,

NEVER TO BE SEEN AGAIN.

THE FOLLOWING YEAR, THE ROCK
CLOSED ITS DOORS FOREVER.

BUT DECADES LATER, THE LEGEND
OF THE SPANISH TUNNELS PERSISTS.

IS IT POSSIBLE
THEY ARE STILL HIDDEN

SOMEWHERE ELSE UNDER THE PRISON?

MAYBE FUTURE TECHNOLOGY WILL
REVEAL SOMETHING WE'VE MISSED.

OR MAYBE, LIKE SOME
OF THE INMATES

ONCE INCARCERATED HERE,

SOME SECRETS
WILL NEVER LEAVE ALCATRAZ.

AND NOW I'M HEADING FROM ONE
OF AMERICA'S MOST ICONIC SITES

TO ONE OF ITS MOST MYSTERIOUS--

LAKE MICHIGAN, ONE OF THE FIVE
GREAT LAKES OF NORTH AMERICA

AND A PLACE PERMEATED
WITH LEGENDS AND LORE.

ITS WATERS ARE A TIME CAPSULE
OF LOST HUMAN HISTORY

DATING FROM THE PRESENT
ALL THE WAY BACK

TO OUR EARLIEST
PREHISTORIC ANCESTORS.

AND FOR ME, ONE OF THE MOST
RECENT DISCOVERIES HERE

MAY BE THE MOST PERPLEXING.

WHILE SEARCHING FOR SHIPWRECKS,

A GROUP
OF UNDERWATER ARCHAEOLOGISTS

STUMBLED ON SOMETHING
THEY COULDN'T EXPLAIN.

SONAR SCANS OF THE LAKE BOTTOM

REVEALED
A 1/4-MILE LINE OF ROCKS

CULMINATING
IN AN ALMOST PERFECT HEXAGON--

AN ANCIENT, MYSTICAL SYMBOL.

THE ROCKS ALSO LIE IN CLOSE
PROXIMITY TO TRIBAL LAND,

WHICH HAS LED MANY TO BELIEVE
THIS IS NO ACCIDENT OF NATURE,

BUT A SACRED, MAN-MADE SITE
LIKE STONEHENGE.

AND THAT'S NOT ALL.

SOME EVEN BELIEVE
THEY CAN DECIPHER

A MAN-MADE CARVING ON THE FACE
OF ONE OF THE ROCKS.

THIS RAISES SOME HUGE QUESTIONS.

FOR STARTERS,
IF THIS IS MAN-MADE,

HOW DID IT GET
40 FEET UNDERWATER?

WHO PUT IT THERE, AND WHEN?

AND EVEN MORE PERPLEXING,
WHAT EXACTLY IS IT?

TO PROBE THESE MYSTERIES,

I'M GOING TO EXPLORE THE SITE
UP CLOSE AND PERSONAL

BY DEPLOYING
STATE-OF-THE-ART TECHNOLOGY

THAT CAN CAPTURE THE CONTOURS

OF THE ROCKS
IN UNPRECEDENTED DETAIL.

I THINK THAT'S SOMETHIN'.

FIRST, I NEED
TO TALK TO THE MAN

WHO MADE
THE INITIAL DISCOVERY--

UNDERWATER ARCHAEOLOGIST
DR. MARK HOLLEY.

HE'S, ESSENTIALLY,
THE GATEKEEPER.

IF YOU DON'T GO
THROUGH MARK HOLLEY,

YOU DON'T SEE THE SITE.

HAVING GRANTED ME
SPECIAL ACCESS,

MARK MEETS ME ON THE DOCK

WITH TRIBAL REPRESENTATIVE
HANK BAILEY,

WHO HAS CLOSELY GUARDED
THE SITE SINCE THE DISCOVERY.

WHAT DO WE NEED TO KNOW
WHEN WE GO OUT THERE?

THIS SITE
THAT WE'RE LOOKING AT

IS POSSIBLY
A CEREMONIAL SITE.

WE DON'T WANT THE LOCATION
OF THIS KNOWN YET.

MARK AND HANK
SUSPECT THIS ROCK FORMATION

MAY NOT ONLY BE MAN-MADE,
BUT SACRED.

SO THEY'VE KEPT
ITS LOCATION TOP SECRET.

AND THEY'RE INTENT ON MAKING
SURE IT STAYS THAT WAY.

WE WANT TO HAVE YOU
BLINDFOLDED.

AND JUST TO BE CLEAR, GUYS,

IT'S GONNA BE THE CREW
AND EVERYBODY.

EVERYBODY?EVERYBODY IN YOUR CREW.

SERIOUSLY?
ALL RIGHT.

MARK EVEN MAKES US SURRENDER
OUR CELLPHONES AT THE DOCK

SO WE CAN'T USE GPS
TO PINPOINT OUR LOCATION.

THESE ARE
SOME PRETTY SERIOUS MEASURES

TO PROTECT
A FEW SUBMERGED STONES.

SO I CAN'T HELP BUT WONDER,

"WHAT DO THESE GUYS
KNOW ABOUT THEM THAT I DON'T?"

BUT BEFORE I FIND OUT,
IT'S TIME TO CUT THE CAMERAS.

I'M ON A QUEST TO INVESTIGATE
A MYSTERIOUS PATTERN OF ROCKS

DISCOVERED UNDER LAKE MICHIGAN

THAT SOME ARE CALLING
AMERICA'S UNDERWATER STONEHENGE.

I'VE SEEN THE ORIGINAL
STONEHENGE UP CLOSE MYSELF.

IT'S A MYSTERIOUS SITE
IN SOUTHWESTERN ENGLAND

THAT'S EVEN OLDER
THAN THE EGYPTIAN PYRAMIDS,

DATING TO ABOUT 5,000 YEARS AGO.

IT'S A MEGALITHIC STRUCTURE
MADE OF MASSIVE ROCKS

WEIGHING AS MUCH
AS 50 TONS EACH.

THE ROCKS ARE STACKED
ON TOP OF ONE ANOTHER

AND ARRANGED IN A GIANT CIRCLE.

SO IT'S CLEAR THAT STONEHENGE
IS A MAN-MADE MONUMENT.

BUT THE ORIGIN OF THESE STONES

IN LAKE MICHIGAN
IS LESS OBVIOUS.

WHILE THEY DO SEEM TO FORM
A PERFECT GEOMETRIC SHAPE,

THEY AREN'T STACKED
OR CONNECTED IN THE SAME WAY.

AND WHILE THERE IS EVIDENCE

THAT PREHISTORIC TRIBES
ROAMED THE GREAT LAKES

FOR THOUSANDS OF YEARS,

VERY LITTLE IS KNOWN ABOUT THEM.

AND I HAVEN'T SEEN ANYTHING
REMOTELY RESEMBLING

THIS FORMATION
IN THE ARCHAEOLOGICAL RECORD.

SO, IF THIS IS MAN-MADE,
WHO WOULD HAVE MADE IT, AND WHY?

ONCE WE'RE OUT IN OPEN WATER,

WE'RE ALLOWED TO TAKE OFF
THE BLINDFOLDS

AND TURN THE CAMERAS BACK ON.

SO I JOIN UNDERWATER
ARCHAEOLOGIST MARK HOLLEY

ON THE TOP DECK TO FIND OUT

WHY HE THINKS THIS DISCOVERY
IS SO IMPORTANT.

TELL ME A LITTLE BIT
HOW YOU FOUND IT.

WE WERE LOOKING
FOR A SHIPWRECK.

ALL OF A SUDDEN,
THIS LINE OF STONES COMES UP.

WE HAD NO IDEA
OF WHAT IT WAS,

OTHER THAN IT DIDN'T
LOOK TO BE NATURAL.

IT LOOKED TO BE ARTIFICIAL.

ONE LOOK AT THE OUTLINE
OF THE ROCKS WAS ALL IT TOOK

TO CONVINCE
TRIBAL ELDER HANK BAILEY

THAT THIS IS A CEREMONIAL SITE.

HANK'S ANCESTORS,
THE ANISHINAABE PEOPLE,

WERE AMONG THE FIRST
TO INHABIT THIS AREA.

HE BELIEVES HIS TRIBE'S
PREHISTORIC FOREFATHERS,

HUNTER-GATHERERS
WHO SETTLED THIS AREA

AFTER THE LAST ICE AGE,

PLACED THESE STONES HERE
FOR A SACRED PURPOSE.

WHY IS IT
SO IMPORTANT TO YOU?

ANISHINAABE CULTURE,
WE REFER TO STONES

AS ANIMATE OBJECTS

BECAUSE THEY COME
FROM THE MOTHER,

THE EARTH, WHO IS ALIVE.

WE REFER TO THEM
AS MISHOMIS-- "GRANDFATHER."

THEY REINFORCE THAT WE HAVE
BEEN HERE A LONG TIME.

AND THAT'S WHY
WE'VE BEEN SO PARTICULAR

WITH YOUR CREW ABOUT...

YEAH.
...THE LOCATION.

BUT HOW COULD A SITE 40 FEET
UNDERWATER BE SACRED GROUND?

IT'S UNLIKELY
AN ANCIENT CIVILIZATION

WOULD HAVE DROPPED SIX STONES

INTO SUCH A PERFECT ARRANGEMENT
FROM BOATS ON THE SURFACE.

BUT COULD IT BE POSSIBLE
THAT IN THE TIME

OF HANK'S ANCIENT ANCESTORS,

THIS LAKE BED WAS HIGH AND DRY?

IF SO, THE POSSIBILITY

THAT THIS SITE IS MAN-MADE
IS MORE LIKELY.

WHEN I STARTED
RESEARCHING THIS STORY,

I KNEW THE SIZE OF THE GREAT
LAKES HAD FLUCTUATED OVER TIME,

JUST NOT HOW MUCH
THEY CHANGED OR WHEN.

SO I MET UP WITH LOCAL EXPERT
BRIAN PRICE TO FIND OUT MORE.

BRIAN HAS BEEN STUDYING THIS
PART OF THE COUNTRY FOR DECADES.

AND HE'S NOT THE LEAST BIT
SKEPTICAL ABOUT THE PRESENCE

OF A MAN-MADE ROCK FORMATION
BETWEEN LAKE MICHIGAN.

LAKE LEVELS
HAVE CHANGED DRASTICALLY.

UH-HUH.
BEEN MUCH HIGHER

AND THEN MUCH LOWER

AND THEN MUCH HIGHER AGAIN.

BRIAN EXPLAINS
THAT WHEN THE GLACIERS

FROM THE LAST ICE AGE
BEGAN TO MELT,

LAKE MICHIGAN STARTED TO SWELL.

BUT WHEN THE MELTING ICE
EXPOSED A NEW CHANNEL

TO THE ST. LAWRENCE RIVER,
THE MELTWATER DRAINED OFF,

AND THE LAKE
SHRUNK DRAMATICALLY.

WE KNOW FOR SURE
THAT, 10,500 YEARS AGO,

THE WATER LEVEL
IN THE LAKE MICHIGAN BASIN

DROPPED PRECIPITOUSLY
AND DRAINED

TO A MUCH LOWER LEVEL
FOR AT LEAST 3,500 YEARS.

YOU'RE SAYING THAT THAT AREA

WAS NOT UNDERWATER
10,000 YEARS AGO?

RIGHT.
5,000 YEARS AGO,

THE WATER
OVERRAN THAT SITE AGAIN

AS THE WATER LEVELS RAISED
IN THE LAKE MICHIGAN BASIN.

RIGHT.

AND I'LL TELL YOU
SOMETHING MORE.

WE KNOW
THAT THE AREA WAS SETTLED.

IT WOULD HAVE BEEN
A WONDERFUL PLACE FOR PEOPLE

TO LIVE NEAR THE COASTLINE
CLOSE TO RESOURCES.

TRANSPORTATION'S EASY.

IT MEANS THAT PEOPLE COULD HAVE
PUT THOSE STONES THERE.

ABSOLUTELY.

SO, BASED ON BRIAN'S RESEARCH,
IT'S ENTIRELY POSSIBLE

THAT HUMANS
COULD HAVE BUILT THIS SITE.

BUT THE QUESTION REMAINS,
DID THEY?

AS A SCIENTIST,
I KNOW THE ONLY WAY

TO DETERMINE
THE TRUE NATURE OF THIS SITE

IS WITH EMPIRICAL EVIDENCE.

SO I NEED A CLOSEUP VIEW
OF THE ROCKS

AND NOT JUST
THE FLAT SONAR IMAGES

I'VE SEEN FROM ABOVE.

I NEED TO SEE THEM FROM BELOW.

WE GOT TWO PROPELLERS
IN THE BACK.

WE GOT A PROPELLER ON TOP,
PROPELLERS ON THE SIDES.

SO A MEMBER OF MARK'S TEAM

HELPS ME PREP
THE CAMERA-MOUNTED R.O.V.,

OR REMOTELY OPERATED VEHICLE.

THIS ONE, NICKNAMED JAKE,

IS FULLY LOADED
WITH THREE CAMERAS,

A GRASPING CLAW,

MEASURING LASERS,
AND GPS NAVIGATION.

IT CAN WITHSTAND
THE FRIGID WATER TEMPERATURE

OF LAKE MICHIGAN
BETTER THAN ANY HUMAN.

AND IT CAN DIVE
TO 1,000 FEET DEEP.

ALL RIGHT. LOOKS
LIKE WE'RE IN A GOOD PLACE.

SO WE'RE GONNA GO DOWN.

SO, WE ARE ON THE BOTTOM.

THE R.O.V. GIVES ME
A MUCH CLOSER LOOK AT THE SITE

THAN THE RADAR SCANS.

AS A MARINE BIOLOGIST,
I'VE SPENT A LOT OF TIME

EXPLORING UNDER WATER THIS WAY.

AND AT FIRST GLANCE,
NO OBVIOUS TRACES

OF HUMAN PRESENCE
JUMP OUT AT ME.

BUT ONE STONE IN PARTICULAR

HAS DRAWN SPECIAL ATTENTION
FROM MARK'S TEAM...

I THINK THAT MIGHT BE
OUR STONE HERE.

...BECAUSE THEY THINK IT HAS
A CARVING ETCHED ONTO ITS FACE.

YEAH, YOU CAN SEE IT LOOKS
PRETTY ROUNDED OFF.

SO I THINK
THIS FACE RIGHT HERE--

THIS LINE HERE,
THIS LINE HERE,

I THINK, MAKES UP
THE POTENTIAL CARVING.

FINDING A CARVING WOULD CONFIRM
THAT THIS SITE IS MAN-MADE

AND OPEN UP
A WHOLE NEW SET OF QUESTIONS.

BUT THE RESOLUTION
FROM THE R.O.V.'s CAMERA

ISN'T SHARP ENOUGH
TO TELL FOR SURE.

YEAH.
I MEAN, HONESTLY,

IT IS REALLY HARD TO SEE.

I MEAN, IT'S SOMEWHAT LOW RES.
IT'S HARD TO TELL RIGHT NOW.

I THINK WHAT WE'RE GONNA HAVE
TO DO IS GET IN THE WATER.

WE DON'T EXCAVATE ANYTHING.
WE'RE NOT TOUCHING ANYTHING.

WE'RE JUST GOING DOWN,
LOOKING, TAKING PICTURES.

OKAY.

MARK AND HANK HAVE AGREED

TO ALLOW JUST ONE DIVE
TO THE SITE.

NOW I'M AMPED.

IF I'M GOING TO SOLVE
THE MYSTERY

OF THIS UNDERWATER STONEHENGE,
THIS IS MY ONE SHOT.

I'M DESCENDING
TO THE BOTTOM OF LAKE MICHIGAN

TO GET A CLOSER LOOK
AT A MYSTERIOUS SITE

SOME HAVE CALLED
AMERICA'S UNDERWATER STONEHENGE.

AT FIRST, I EXPECTED
THIS PECULIAR-SHAPED FORMATION

WOULD TURN OUT TO BE
JUST A NATURAL ANOMALY.

BUT I'M STARTING TO BELIEVE
IT MAY BE SOMETHING MORE.

FOR ONE THING, THE GEOLOGICAL
RECORD INDICATES THIS SITE,

NOW 40 FEET UNDERWATER,

MAY HAVE BEEN ON DRY LAND
FOR MILLENNIA

AFTER HUMANS ARRIVED HERE.

AND ARCHAEOLOGICAL EVIDENCE
SUGGESTS THIS AREA WAS INHABITED

BY PREHISTORIC AMERICANS
LONG BEFORE THAT.

BUT MOST STRIKING ARE THE IMAGES
FROM OUR R.O.V. CAMERA

THAT SHOW WHAT COULD BE
A MAN-MADE CARVING

ON ONE OF THE ROCKS.

COULD THIS BE SOME
OF AMERICA'S OLDEST ARTWORK

OR JUST ANOTHER RANDOM ACT
OF NATURE?

THERE'S ONLY ONE WAY
TO FIND OUT.

I CAN MAKE OUT
A SERIES OF INDENTATIONS

THAT COULD BE A CARVING.

BUT THE VISIBILITY IS TOO POOR
FOR ME TO TELL FOR SURE.

SO I'M GOING TO TRY OUT
A NEW PIECE OF TECHNOLOGY

THAT SEES THE ROCK
BETTER THAN I CAN--

AN ADVANCED TECHNIQUE
CALLED STEREO PHOTOGRAMMETRY.

AND IT ALLOWS SCIENTISTS
TO CREATE 3-D MODELS

FROM TWO-DIMENSIONAL
PHOTOGRAPHS.

PLACING SCALE BARS AROUND
THE ROCK AS A POINT OF REFERENCE

AND PHOTOGRAPHING IT
FROM MULTIPLE ANGLES,

I'LL BE ABLE TO STITCH TOGETHER
A DIGITAL MODEL OF THE ROCK

FOR MORE DETAILED
DIGITAL INSPECTION.

A LINE OF SIGHT IS CONSTRUCTED
FROM THE CAMERA

TO VARIOUS COMMON POINTS
ON THE ROCK.

THEN, THE TRIANGULATION
OF THESE LINES

FROM MULTIPLE PHOTOS
CAN DETERMINE

THE 3-D LOCATION OF THOSE POINTS

AND BUILD AN ACCURATE
3-D RENDERING OF THE ROCK,

WHICH I CAN ANALYZE IN DETAIL
ONCE I'M BACK ON DRY LAND.

AFTER I'VE GATHERED
ALL OF THE EVIDENCE I CAN,

WE MAKE OUR WAY BACK TO SHORE.

I'M CONVINCED
THERE'S SOMETHING PECULIAR

AT THE BOTTOM OF LAKE MICHIGAN.

HOPEFULLY, THE 3-D MODEL
WILL GIVE ME THE TOOLS

I NEED TO DETERMINE THE TRUTH

ABOUT THESE ROCKS
ONCE AND FOR ALL.

IF THIS SITE
REALLY WAS MADE BY MAN,

IT MUST HAVE SERVED
A SPECIFIC PURPOSE.

SO, WHAT COULD IT BE?

I KNOW
THAT SEVERAL EARLY CULTURES

USED STONES
TO TRACK THE POSITION OF THE SUN

AND THE STARS IN THE SKY.

IN FACT, THERE'S A WELL-KNOWN
STONE FORMATION IN WYOMING

CALLED THE MEDICINE WHEEL,

WHERE THE ROCKS
ALIGN WITH CERTAIN STARS

ON SPECIFIC DATES OF THE YEAR.

IT WAS AN EFFECTIVE TOOL
TO PREDICT

WHEN THE SUMMER SOLSTICE
WOULD OCCUR,

ALLOWING NATIVE PEOPLE
TO BETTER TIME

WHEN TO HARVEST THEIR CROPS.

COULD THAT BE WHAT'S HAPPENING
WITH THESE ROCKS

RIGHT HERE IN LAKE MICHIGAN?

WHEN IMAGES
OF OUR UNDERWATER ROCKS

ARE COMPARED
WITH THE MEDICINE WHEEL,

I NOTICE A GLARING OMISSION.

NOT ONLY DOES THE MEDICINE WHEEL
HAVE 28 AXES,

PROVIDING MORE ACCURATE LINES
OF MEASUREMENT,

BUT OUR SITE DOESN'T HAVE

A PRECISELY MARKED
CENTRAL FOCAL POINT,

A KEY FEATURE
IF YOU'RE TRYING TO CHART

THE SUN'S POSITION IN THE SKY.

SO IT SEEMS UNLIKELY
THIS HEXAGON OF SIX ROCKS

WAS USED TO TRACK
THE SUN OR STARS.

THE STORY BEHIND THESE STONES
STILL ELUDES ME.

BUT THERE'S ONE MORE MAJOR CLUE

THAT COULD CRACK
THE CASE-- THE CARVING.

TRYING TO ORIENT MYSELF HERE.

THERE'S DEFINITELY
SOMETHING THERE.

I NEED TO GET A CLOSER LOOK.
LET ME GET MY TABLET OUT HERE.

ALL RIGHT, IF I JUST KIND OF
OUTLINE THESE INDENTATIONS,

BASICALLY TAKING EVERYWHERE
WHERE I SEE AN INDENTATION...

STRIPE THERE.
STRIPE DOWN THIS WAY.

THERE'S, LIKE, SOMETHIN' THERE.

LOOKS TO ME LIKE MAYBE THESE
ARE SOME SORT OF LEGS IN HERE.

THIS COULD BE AN EAR.

IF YOU LOOK AT THIS,
AND YOU START SKETCHING IT,

ONCE YOU OUTLINE THE LINES,
IT LOOKS LIKE WE--

IT LOOKS LIKE
A FREAKIN' MASTODON.

UNBELIEVABLE.

A MASTODON CARVING ON A ROCK

THAT HASN'T SEEN DAYLIGHT
IN AT LEAST 5,000 YEARS.

THIS IS HUGE.

MASTODONS
ARE AN ANCIENT ANCESTOR

OF ELEPHANTS
AND WOOLLY MAMMOTHS.

THEY WERE ONE
OF THE LARGEST LAND ANIMALS

EVER TO ROAM NORTH AMERICA,

STANDING UP TO 10 FEET TALL
AND WEIGHING UPWARDS OF 6 TONS.

MASTODON FOSSILS
HAVE BEEN UNCOVERED

ALL ACROSS THE EASTERN U.S.,
INCLUDING IN PLACES

THAT COULD HAVE BEEN LINKED
TO LAKE MICHIGAN

ALONG THE SAME MIGRATION ROUTE.

IN NEIGHBORING OHIO,
AT THE BURNING TREE GOLF COURSE

OUTSIDE OF COLUMBUS,

EXCAVATORS DIGGING IN A PEAT BOG

UNCOVERED
THE MOST COMPLETE SKELETON

OF AN AMERICAN MASTODON
EVER FOUND.

BUT MORE RECENTLY,
A DISCOVERY IN A FLORIDA LAKE

LED SCIENTISTS
TO A STARTLING REVELATION.

BUTCHERED MASTODON BONES
WERE FOUND ACCOMPANIED

BY MAN-MADE TOOLS,

PROVING THAT MASTODONS
AND HUMANS COEXISTED

IN NORTH AMERICA
THOUSANDS OF YEARS EARLIER

THAN PREVIOUSLY THOUGHT--

BETWEEN ROUGHLY 15,000
AND 10,000 YEARS AGO

BEFORE MASTODONS WENT EXTINCT,

WHICH GIVES US
AN APPROXIMATE DATE

AS TO WHEN OUR SITE
MAY HAVE BEEN MADE.

AND IT COULD BE AT LEAST
TWICE AS OLD AS STONEHENGE.

SO, IF THIS IS
A MASTODON CARVING,

IT STRONGLY SUGGESTS
THIS SITE IS MAN-MADE

AND DATES IT
TO AT LEAST 10,000 YEARS AGO.

BUT ONE QUESTION
STILL REMAINS--

WHAT PURPOSE DID IT SERVE?

I'M SETTING OUT TO SOLVE
THE FINAL PIECE

OF OUR PREHISTORIC MYSTERY

WITH A LITTLE HELP
FROM AN ARCHAEOLOGIST

WHOSE OWN RECENT DISCOVERY
COULD BE THE LAST MISSING PIECE.

LET ME SHOW YOU WHAT
WE'VE SEEN IN LAKE HURON.

YOU PROBABLY SAW SOMETHING

THAT LOOKED PRETTY SIMILAR
TO THAT, RIGHT?

YEAH.
JUST LIKE THAT.

MY INVESTIGATION
INTO A MYSTERIOUS PATTERN

OF ROCKS LYING 40 FEET
BELOW LAKE MICHIGAN

HAS YIELDED
SOME INTRIGUING REVELATIONS.

FOR STARTERS, THIS SITE
WAS ON DRY LAND FOR MILLENNIA

DURING A SPAN OF TIME
WHEN PREHISTORIC TRIBES

OF HUNTER-GATHERERS
ROAMED THE CONTINENT.

SO A COMMUNITY OF ANCIENT PEOPLE

COULD, INDEED,
HAVE PLACED THESE ROCKS.

AND THE PRESENCE OF WHAT APPEARS
TO BE A CARVING OF A MASTODON

ON ONE OF THEM IS STRONG
EVIDENCE THAT THEY DID.

BUT ONE KEY QUESTION
STILL REMAINS--

WHY WERE THESE ROCKS PLACED
IN A PERFECT HEXAGONAL SHAPE?

WHAT PURPOSE DID THEY SERVE?

TO FIND OUT, I'M MEETING UP

WITH ARCHAEOLOGIST
DR. JOHN O'SHEA.

RECENTLY, HE MADE A DISCOVERY
IN NEARBY LAKE HURON

WHICH COULD SHED LIGHT
ON OUR MYSTERY.

LET ME SHOW YOU AN EXAMPLE OF
WHAT WE'VE SEEN IN LAKE HURON.

IF YOU LOOK AT THIS,

YOU'LL SEE THAT YOU'VE GOT
THIS LONG LINE

OF KIND OF
EVENLY SPACED ROCKS

OUT WHERE THERE'S
NOTHING ELSE THERE.

YOU PROBABLY SAW SOMETHING

THAT LOOKED PRETTY SIMILAR
TO THAT TODAY, RIGHT?

YEAH.
JUST LIKE THAT.

UNDER LAKE MICHIGAN,
THERE'S A LONG LINE OF ROCKS

LEADING DIRECTLY TO OUR HEXAGON.

AND HUNDREDS OF MILES AWAY

UNDER A COMPLETELY
DIFFERENT LAKE,

THERE APPEARS TO BE
A VERY SIMILAR CONFIGURATION.

SO THERE COULD DEFINITELY
BE A CONNECTION HERE.

WHAT DO YOU THINK IT IS?

I CAN MAKE
A PLAUSIBLE ARGUMENT

THAT IT'S A HUNTING STRUCTURE
THAT THE ANCIENT HUNTERS USED

KNOWN AS A DRIVE LANE.

DR. O'SHEA EXPLAINS
THAT DRIVE LANES

HAVE BEEN USED BY HUNTERS
FOR THOUSANDS OF YEARS

AS A WAY TO HERD
LARGE GROUPS OF ANIMALS

ALONG A SET PATH
TOWARD A KILL ZONE,

WHERE HUNTERS LIE IN WAIT.

I'D LIKE TO SHOW YOU ONE
THAT IS STILL USED TO THIS DAY.

THIS IS THE EDGINGTON DRIVE
LANE IN NORTHERN CANADA.

YOU SEE THIS LINE OF STONES
BEHIND THE HUNTER.

THAT'S ACTUALLY
A CARIBOU DRIVE LANE.

AND IN THE FOREGROUND,
YOU'LL SEE A CIRCLE.

AND THAT CIRCLE
IS A HUNTING BLIND

THAT LOOKS A LOT
LIKE THE ONE YOU WERE ON.

THE CARIBOU
WON'T JUST STEP OVER THAT?

THEY WILL NOT.

THAT'S ENOUGH TO CHANNEL
THE MOVEMENT OF THE ANIMALS.

MANY PREY SPECIES
THAT LIVE IN HERDS

INSTINCTIVELY AVOID
CROSSING BARRIERS,

EVEN IF THEY'RE
JUST PAINTED LINES.

I GREW UP IN NEBRASKA,
AND AT CATTLE CROSSINGS,

THEY PAINT STRIPES.

AND THE CATTLE
WON'T STEP IN THE STRIPE

BECAUSE THEY'RE AFRAID
OF THEIR HOOF GOING THROUGH IT

LIKE IT'S--
LIKE IT'S AN OPENING.

THE ANCIENT HUNTERS KNEW
THAT THEY COULD SUGGEST

WHERE THE ANIMALS OUGHT
TO MOVE-- INTO ZONES,

WHERE THEY COULD
THEN AMBUSH THEM.

THE DISCOVERY
OF THESE ANCIENT DRIVE LANES

GIVES US SOME KEY INSIGHT
INTO THE ANCIENT HUNTERS

WHO USED THEM.

THEIR SIZE AND SCALE
SUGGEST THEY WERE CREATED

BY A LARGE GROUP
OF ORGANIZED PEOPLE

CAPABLE OF WORKING TOGETHER
AS A TEAM.

MAYBE FUTURE EXCAVATIONS

WILL REVEAL MORE
ABOUT THE HUNTERS AND THE HUNTED

WHO ROAMED THE GREAT LAKES
IN PREHISTORIC TIMES.

BUT OUR SCIENTIFIC ANALYSIS
OF THIS LONG-LOST ROCK FORMATION

HAS ALREADY TAUGHT ME MORE
THAN I EVER THOUGHT IT COULD,

LIKE THE FACT
THAT THE GREAT LAKES

WERE ONCE MUCH SMALLER
THAN THEY ARE NOW,

THAT MASTODONS AND PEOPLE
CROSSED PATHS ON A LANDSCAPE

NOW LOST BENEATH THE WAVES,

AND THAT
OUR PREHISTORIC ANCESTORS

HAD ADVANCED STRATEGIES

FOR ROUNDING UP
VAST HERDS OF PREY.

THIS CURIOUS COLLECTION
OF STONES

HAS PRESERVED ITS SECRETS
FOR MILLENNIA.

IT JUST NEEDED SCIENCE
TO DECODE THEM.