NARRATOR: CONSTRUCTION IN 21ST CENTURY CHINA IS PUSHING THE LIMITS ON FUTURISTIC DESIGN AND INGENUITY.

BUT ONE NEW BUILD IS HOPING TO STAND OUT FROM THE CROWD.

[MAN SPEAKING MANDARIN] NARRATOR: A TEAM OF THE COUNTRY'S TOP ARCHITECTS AND ENGINEERS IS PLANNING TO PUT THEIR CITY ON THE MAP BY TURNING THIS, A VAST ABANDONED LIMESTONE QUARRY, INTO THIS... A MULTIMILLION DOLLAR FUTURISTIC LANDMARK WINTER SPORTS RESORT.

MAN: IT'S LIKE A METAL UFO SUSPENDED ON THE CLIFF.

IT'S AMAZING.

NARRATOR: BUT IF THEY'RE TO SUCCEED, THEY MUST BATTLE A POTENTIALLY LETHAL SITE... MAN: AS AN ARCHITECT, I LOOK AT THE ICE WORLD, AND I FEEL THEY ARE IN FOR A LONG HAUL AND VERY TOUGH CHALLENGE.

[ALL GRUNTING] NARRATOR: A PUNISHING SCHEDULE... MAN: IT'S NOT A TRADITIONAL BUILDING LIKE WE ARE USED TO DESIGNING.

THAT'S A CHALLENGE.

NARRATOR: AND EVEN NATURE ITSELF.

[MAN SPEAKING MANDARIN] NARRATOR: THIS IS ICE WORLD, AND IT IS AN IMPOSSIBLE BUILD.

IMPOSSIBLE BUILDS WAS MADE POSSIBLE IN PART BY CONTRIBUTIONS TO YOUR PBS STATION FROM VIEWERS LIKE YOU.

THANK YOU.

CHINA.

A COUNTRY COVERING OVER 3.7 MILLION SQUARE MILES... WITH A POPULATION OF OVER ONE BILLION.

500 MILES FROM SHANGHAI IS CHANGSHA, HOME TO 8 MILLION PEOPLE, BUT LITTLE KNOWN OUTSIDE OF CHINA.

NOW IT'S DESPERATE TO PUT ITSELF ON THE MAP AND ATTRACT BOTH INTERNAL AND EXTERNAL TOURISM.

PLANS TO BUILD THE WORLD'S TALLEST BUILDING HERE IN 2013 COLLAPSED JUST DAYS AFTER GROUNDWORK BEGAN.

BUT CHANGSHA HAS SPOTTED ANOTHER OPPORTUNITY TO BECOME A DESTINATION CITY.

THE 2022 WINTER OLYMPICS IN CHINA INSPIRED ONE GROUP OF GROUNDBREAKING ARCHITECTS TO MAKE CHANGSHA HOME TO THE MOST SPECTACULAR INDOOR SKI RESORT IN THE WORLD.

IT'S REALLY AN AMBITIOUS PROJECT.

BUT TO ACHIEVE THAT, WE ARE FACING A LOT OF CHALLENGES.

NARRATOR: THE DESIGN THAT ARCHITECT WANG TAO AND THE DEVELOPMENT TEAM HAVE BEEN HIRED TO BRING TO LIFE IS THIS...

THE DEEP PIT ICE AND WATER WORLD.

WHEN COMPLETE, IT WILL BE A 400,000 SQUARE FOOT FUTURISTIC RESORT...

APPEARING TO FLOAT HIGH ABOVE A TRANQUIL LAKE 330 FEET BELOW.

AT ITS CENTER, THE STAR ATTRACTION, A 500-FOOT-LONG INDOOR SKI SLOPE, COMPLETE WITH CABLE CARS AND TRADITIONAL ALPINE BUILDINGS.

ON THE ROOF, A MASSIVE WATER PARK.

AND OVERLOOKING THE WHOLE STRUCTURE, A LUXURIOUS 5-STAR HOTEL TO ACCOMMODATE THE TOURISTS THE INVESTORS HOPE WILL FLOCK TO THE SITE FROM ACROSS CHINA AND THE WORLD.

WANG: IT'S LIKE A METAL UFO SUSPENDED ON THE CLIFF.

IT'S AMAZING.

NARRATOR: THE CHALLENGE NOW FOR THE STRUCTURAL ENGINEERS HEADED UP BY ZHOU JAIN IS TO MAKE THE FLAMBOYANT DESIGN A REALITY.

IT'S NOT A TRADITIONAL BUILDING LIKE WE ARE USED TO DESIGNING.

IT'S MORE LIKE A BRIDGE.

THAT'S A CHALLENGE FOR OUR DESIGN AND THE SCALE OF THE CONSTRUCTION.

THIS ICE WORLD PROJECT LOOKED IMPOSSIBLE WHEN WE FIRST SEE IT.

BUT WHEN WE GO INTO EVERY DETAIL OF IT, AND NOW WE ARE CONFIDENT THAT IT WILL BE A REALITY.

NARRATOR: THE TEAM MAY BE CONFIDENT, BUT THEY'LL HAVE THEIR WORK CUT OUT.

IF THE SPACE AGE DESIGN WASN'T COMPLEX ENOUGH, THIS IS THE LOCATION FOR THE BUILD-- AN ABANDONED HUNDRED-YEAR-OLD LIMESTONE QUARRY ON THE FAR REACHES OF CHANGSHA'S CITY LIMITS.

UNUSED FOR DECADES, THE SITE ALONE WILL PUSH THE TEAM'S INGENUITY AND ENDURANCE TO ITS LIMITS.

THE SHEER AMBITION OF THE PROJECT IS ALREADY ATTRACTING ATTENTION FROM AROUND THE WORLD.

MAN: MYSELF AS AN ARCHITECT, I LOOK AT THE ICE WORLD, AND I FEEL THEY ARE IN FOR A LONG HAUL AND VERY TOUGH CHALLENGE.

TO THE OUTSIDER, IT MAY SEEM QUITE IMPOSSIBLE BECAUSE OF THE CHALLENGES THAT ARE FACED BY THE LOCATION, BY THE UNIQUENESS OF THE GEOLOGY OF THIS SITE.

IN REALITY, THESE ISSUES CAN BE OVERCOME, BUT THE DESIGNERS HAVE TO BE FLEXIBLE IN HOW THEY APPROACH THEM AND HAVE TO BE ABLE TO ADAPT THEIR DESIGN TO THE CONDITIONS THAT THEY ENCOUNTER ON SITE.

NARRATOR: OCTOBER 2014, AND WORK PREPARING THE ABANDONED QUARRY FOR CONSTRUCTION BEGINS.

THE DESIGN MAY BE SET, BUT THE QUARRY FLOOR IS CURRENTLY SUBMERGED UNDER 28 MILLION SQUARE FEET OF WATER.

UNTIL IT'S DRAINED, THE TEAM IS WORKING BLIND.

THE BOTTOM OF THE QUARRY WILL NEED TO BE SOLID ENOUGH TO SUPPORT 360,000 TONS OF STEEL AND CONCRETE.

BUT UNTIL THE BEDROCK IS EXPOSED, THE TEAM WON'T BE ABLE TO WORK OUT IF THAT'S EVEN POSSIBLE.

THAT MEANS PUMPING OUT THOUSANDS OF CUBIC FEET OF SITTING WATER.

AND THAT ISN'T THE ONLY PROBLEM ICE WORLD'S ENGINEERS ARE FACING.

THE CLIMATE IN THIS PART OF CHINA IS SUB-TROPICAL.

THAT MEANS HIGH HUMIDITY AND AN AVERAGE YEARLY RAINFALL OF 56 INCHES.

ON A BAD DAY, OVER 3,000 CUBIC FEET OF RUN-OFF WILL END UP IN THE QUARRY.

THE DAUNTING TASK OF DRAINING THE PIT AND KEEPING IT DRY THROUGHOUT CONSTRUCTION FALLS TO WATER ENGINEER LUI BO.

[SPEAKING MANDARIN] NARRATOR: TO KEEP ON TOP OF THE ALMOST CONSTANT DELUGE, LUI HAS INSTALLED THIS SYSTEM OF 10 HEAVY DUTY PUMPS.

WITHOUT THIS VITAL EQUIPMENT, THE SITE WILL QUICKLY START TO FILL UP AGAIN.

[LUI SPEAKING MANDARIN] NARRATOR: FOR WEEKS, THE PUMPS WORK 24/7.

BUT BY LATE SPRING 2015, THE BOTTOM OF THE PIT IS FINALLY EXPOSED.

AND THAT REVEALS THE TEAM'S WORSE NIGHTMARES.

INSTEAD OF SOLID GRANITE BEDROCK, THE QUARRY FLOOR IS COVERED IN A THICK LAYER OF LIMESTONE.

WORSE STILL, IT'S BEEN ATTACKED BY ACIDIC RAINWATER, A RESULT OF CHINA'S HEAVY POLLUTION.

FOR THE ENGINEERS, IT'S THE CONSTRUCTION EQUIVALENT OF BUILDING ON SWISS CHEESE.

BECAUSE THERE ARE MANY CRACKS IN THE ROCKS, WHEN THE RAIN GOES THROUGH THESE CRACKS, IT MAY ERODE THE ROCKS AROUND THAT AND FORM BIG HOLES.

THESE CAVITIES MAY CAUSE MANY DIFFICULTIES FOR STRUCTURAL DESIGN BECAUSE THE ROCK CANNOT BEAR THE LOAD.

NARRATOR: SITE DIRECTOR LI XIAOGUANG IS RESPONSIBLE FOR IDENTIFYING ANY AREAS WITHIN THE QUARRY FLOOR THAT ARE STRONG ENOUGH TO SUPPORT A STRUCTURE THE SIZE OF ICE WORLD.

[SPEAKING MANDARIN] NARRATOR: SAMPLES ARE EXTRACTED FROM THE QUARRY FLOOR, THEN SENT TO BE PRESSURE TESTED AT A LOCAL LABORATORY IN CHANGSHA.

FOR THE FLOATING DESIGN TO WORK, THE ROCK WILL HAVE TO WITHSTAND HUNDREDS OF TONS OF PRESSURE TO COPE WITH THE MASSIVE WEIGHT EXERTED BY THE FEW FOUNDATION SUPPORTS BENEATH THE STRUCTURE.

TO GUARANTEE THE ROCK AT EACH SPECIFIED LOCATION IS UP TO THE JOB, EACH SAMPLE MUST BE TESTED TO DESTRUCTION.

[MAN SPEAKING MANDARIN] [CLANG] NARRATOR: IT'S BAD NEWS.

[MAN SPEAKING MANDARIN] NARRATOR: THE FIRST SAMPLE HAS FALLEN WELL SHORT OF THE STRICT REQUIREMENTS.

AND IT'S NOT ALONE.

TWO MONTHS OF FAILED PRESSURE TESTS REVEAL NOWHERE ON THE FLOOR OF THE PIT IS STABLE ENOUGH TO SUPPORT THE WEIGHT OF THE CURRENT STRUCTURAL DESIGN.

10 MONTHS INTO THE SCHEDULE, AND ALL THERE IS TO SHOW FOR IT IS A MUDDY HOLE IN THE GROUND.

IF ICE WORLD IS TO SUCCEED, THE TEAM MUST GO BACK TO THE DRAWING BOARD AND RETHINK THEIR BUILD.

WE NEED TO FIND THE EXACT POSITION OF THESE CAVITIES BEFORE CONSTRUCTION AND TRY TO AVOID THEM OR TO FILL THEM WITH CONCRETE TO STRENGTHEN THE ROCK.

THE CIRCUMSTANCE IS NOT SO GOOD AS EXPECTED, SO WE NEED TO MAKE MANY CHANGE TO ACCOMMODATE THESE CONDITIONS TO MAKE THE PROJECT WORK.

NARRATOR: BUILDING A LUXURY SKI RESORT IN A LIMESTONE QUARRY WAS ALWAYS GOING TO BE A PROJECT OF UNRIVALLED AMBITION.

BUT THE DEVELOPERS ARE CONVINCED IT'S A RISK AND A $300 MILLION INVESTMENT WORTH TAKING.

THE OLYMPIC GAMES CAN GENERATE BILLIONS OF DOLLARS FOR THE CHINESE ECONOMY, AND EVEN NOW, YEARS BEFOREHAND, INTEREST IN WINTER SPORTS ACROSS CHINA HAS ALREADY SKY-ROCKETED.

TO TAKE FULL ADVANTAGE OF THE POPULARITY BOOM AND TURN COLD INTO GOLD, THE COUNTRY IS BUILDING 800 NEW SKI RESORTS, BUT CHANGSHA'S ICE WORLD WILL BE THE JEWEL IN THE CROWN.

FUNDED BY AN INVESTMENT TEAM LEAD BY LONG WON CHIN, THE ULTIMATE DREAM IS FOR THIS RESORT TO BECOME CHINA'S NUMBER ONE INDOOR WINTER SPORTS DESTINATION.

[SPEAKING MANDARIN] NARRATOR: EXPECTATIONS ARE HIGH, BUT OVER A YEAR AFTER WORK ON THE QUARRY FIRST STARTED, THE GROUND WORKS HAVE YET TO BEGIN.

AN EXPLOSIVES TEAM IS NOW BLASTING LARGE AREAS THROUGHOUT THE QUARRY TO TRY TO REACH SOLID ROCK... [SHOUTING IN MANDARIN] CAPABLE OF BEARING THE WEIGHT OF THE PLANNED STRUCTURE.

[SHOUTING IN MANDARIN] IT'S A DANGEROUS JOB MADE MORE COMPLEX BY THE NEED FOR PRECISION BLASTING ONCE THEY GET WITHIN 3 FEET OF THE BEDROCK.

[SPEAKING MANDARIN] NARRATOR: AS THE BLAST TEAM RETREAT TO A SAFE DISTANCE, CHE DETONATES THE CHARGE... AND MORE WEIGHT-BEARING ROCK IS EXPOSED.

[SPEAKING MANDARIN] NARRATOR: AFTER 13 MONTHS OF PREPARATION, HAVING REMOVED MORE THAN 7 BILLION TONS OF SOIL, BLASTED OVER A 100,000 TONS OF LIMESTONE, AND TESTED HUNDREDS OF ROCK SAMPLES, WORK ON THE FOUNDATIONS CAN BEGIN.

BUT ICE WORLD WILL NO LONGER HAVE THE APPEARANCE OF A FLOATING STRUCTURE AS ORIGINALLY INTENDED.

THE POOR CONDITION OF THE QUARRY HAS FORCED THE DESIGN TEAM TO RADICALLY RETHINK THEIR VISION.

THE REVISED STRUCTURE WILL NOW SIT ON 48 SUPPORT COLUMNS 300 FEET TALL, MADE FROM STEEL AND SCULPTED CONCRETE.

A MASSIVE FLOOR SLAB WILL SIT ON TOP.

BUT TO REDUCE THE PRESSURE ON THE PIT FLOOR BELOW, IT WILL PARTLY REST ON A LEDGE CARVED OUT OF THE QUARRY WALLS.

THE NEW DESIGN WILL MEAN THE BUILDING IS SUPPORTED BOTH VERTICALLY AND HORIZONTALLY WITHOUT EVER EXERTING EXCESS PRESSURE ON THE QUARRY.

YOU CAN IMAGINE OUR PROJECT IS LIKE A TABLE WITH VERY HEAVY LOADS ON THAT AND WITH MANY LEGS.

SOME OF THEM ARE LONG, SOME OF THEM ARE SHORT.

SOME OF THEM ARE ON THE BOTTOM OF THE PIT.

NARRATOR: THE FIRST STEP FOR THE TEAM IS TO RESHAPE THE QUARRY TO FIT THE NEW FOUNDATION SYSTEM.

IT'S CRUCIAL THEY GET THIS RIGHT.

ANY MISTAKES NOW COULD MEAN THE QUARRY WALLS WILL CAVE INWARDS LATER UNDER THE HUGE LOAD OF THE MAIN STRUCTURE.

TO ENSURE THE PROCESS DOESN'T WEAKEN THE FRAGILE QUARRY EVEN MORE, THE TEAM HAVE DECIDED NOT TO USE HEAVY DRILLING EQUIPMENT TO CREATE THE NATURAL SUPPORTS.

INSTEAD, THEY WILL CARVE THEM OUT.

THIS CREATES FAR LESS VIBRATION, BUT IT'S TIME CONSUMING, BACK-BREAKING WORK.

THE MAN RESPONSIBLE FOR MASTERMINDING THIS CRITICAL STAGE OF CONSTRUCTION IS SITE MANAGER XIA PING.

[SPEAKING MANDARIN] NARRATOR: ONLY WHEN EVERY PRESSURE POINT MEETS THE STRICT WEIGHT-BEARING CAPACITY WILL THE CONSTRUCTION OF THE MAIN ICE WORLD STRUCTURE BEGIN.

[SPEAKING MANDARIN] NARRATOR: 7 MONTHS HAS PAST SINCE THE QUARRY WAS FIRST DRAINED.

THE UNEXPECTED GROUND CONDITIONS HAVE PUT CONSTRUCTION WEEKS BEHIND SCHEDULE.

AND NOW IT'S RAINING HARD.

IT'S NOT MONSOON SEASON, BUT THE WATER PUMPS ARE ONCE AGAIN HAVING TO WORK AROUND THE CLOCK TO KEEP BACK THE RELENTLESS TIDE OF RAINWATER.

DESPITE THE TREACHEROUS CONDITIONS, THE SLIP IN THE SCHEDULE MEANS THE FOUNDATIONS TEAM MUST PUSH ON.

♪ AS THEY EXCAVATE HUNDREDS MORE TONS OF BEDROCK FROM THE QUARRY FLOOR, A FLEET OF MONSTER TRUCKS SHUTTLES THE DEBRIS UP A NEWLY COMPLETED ROAD.

IT WAS BUILT TO HANDLE THE HEAVY MACHINERY, BUT THE UNSEASONAL CONDITIONS ARE MAKING WHAT WAS A RELATIVELY EASY JOURNEY PERILOUS.

[SPEAKING MANDARIN] NARRATOR: WHEN DRY, DRIVERS CAN MAKE THE JOURNEY TO AND FROM THE QUARRY FLOOR DOZENS OF TIMES A DAY.

NOW JUST ONE ASCENT IS PROVING ALMOST IMPOSSIBLE.

[SPEAKING MANDARIN] NARRATOR: DESPITE THE DANGER OF THE SCHEDULE SLIPPING EVEN FURTHER, SITE MANAGER XIA PING HAS NO OPTION BUT TO ORDER THE WORK TO STOP.

[SPEAKING MANDARIN] NARRATOR: AS THE INTENSITY OF THE RAIN INCREASES, THE UNSTRENGTHENED SIDES OF THE QUARRY BEGIN TO CRUMBLE, CAUSING POTENTIALLY LETHAL ROCK FALLS.

AND FOR THE FIRST TIME IN MONTHS, THE QUARRY BEGINS TO FILL UP ONCE AGAIN.

IT'S A DISASTER, BUT THERE IS NOTHING THE TEAM CAN DO BUT LOOK ON AND WAIT.

ICE WORLD IS IN TROUBLE.

BUT DESPITE THE CHALLENGES OF THE LOCATION, THERE IS A RAY OF HOPE.

IT COMES FROM ANOTHER SEEMINGLY IMPOSSIBLE BUILD, AND BY CHINESE STANDARDS, IT'S RIGHT AROUND THE CORNER.

THIS IS THE QUARRY HOTEL, AND JUST LIKE ICE WORLD, IT IS BEING CONSTRUCTED WITHIN AN ABANDONED PIT.

LOCATED 650 MILES AWAY IN SONGJIANG, IT'S BEING BILLED AS THE WORLD'S FIRST UNDERGROUND 5-STAR HOTEL.

THE MAN WHO SUCCESSFULLY HELPED TAKE THIS FANTASTICAL VISION AND TURN IT INTO AN ACTUAL BUILDING IS BRITISH ARCHITECT MARTIN JOCHMAN.

JOCHMAN: TO BUILD A DREAM IS REALLY ABOUT CREATING SOMETHING WHICH HAS A WOW FACTOR, WHICH ACTUALLY WILL ELEVATE THE WHOLE ENVIRONMENT, THE WHOLE PLACE TO ANOTHER LEVEL TO MAKE IT A LANDMARK.

THIS IS IN FACT WHAT MOST CLIENTS THAT I ENCOUNTER IN CHINA SAID, "BUILD US A LANDMARK."

AND IT'S NOT EASY TO BUILD A LANDMARK.

NARRATOR: CONSTRUCTION OF THE $528 MILLION QUARRY HOTEL BEGAN IN 2013.

AND JUST LIKE ICE WORLD, THE TEAM WAS FACED WITH A NUMBER OF UNEXPECTED CHALLENGES.

CREATING A STRUCTURE INSIDE UNUSUAL SITE LIKE A QUARRY WOULD BE IMPOSSIBLE WITHOUT PUSHING THE BOUNDARIES FOR HOW YOU DEAL WITH ALL THE ENGINEERING PROBLEMS.

YOU HAVE TO BE REALLY, REALLY OPEN TO NEW IDEAS.

YOU NEED TO BE ABLE TO SOLVE THESE PROBLEMS.

AS THEY ARE VERY UNIQUE, THEY HAVE NEVER BEEN ENCOUNTERED ON BUILDINGS BEFORE.

NARRATOR: BEING THE FIRST LANDMARK QUARRY PROJECT CREATED NUMEROUS PROBLEMS FOR THE QUARRY HOTEL TEAM.

AND THEY WERE BUILDING INTO SOLID GRANITE.

IN CHANGSHA, THE INSTABILITY OF THE LIMESTONE HAS ADDED YET MORE DIFFICULTY TO AN ALREADY COMPLEX CONSTRUCTION PROCESS.

JOCHMAN: I THINK THE ICE WORLD PROJECT IS ONE OF THE VERY AMBITIOUS OR MOST AMBITIONS PROJECTS AT THE MOMENT, BECAUSE IT TRIES TO BREAK NEW GROUNDS.

IT TRIES TO USE DISUSED INDUSTRIAL QUARRY.

AND THIS HAS ONLY BEEN DONE BEFORE WITH THE QUARRY HOTEL IN SONGJIANG.

NARRATOR: IN 2016, THE END OF CONSTRUCTION IS IN SIGHT FOR THE 370-ROOM QUARRY HOTEL.

THE SAME CANNOT BE SAID FOR ICE WORLD.

THE TEAM IN CHANGSHA STILL HAVE A VERY BIG MOUNTAIN TO CLIMB BEFORE THEIR PROJECT IS ANYWHERE NEAR OPEN FOR BUSINESS.

JOCHMAN: THE DANGER FOR A PROJECT SUCH AS ICE WORLD IS THAT YOU MAY FEEL THAT YOU ARE CONTINUOUSLY PUTTING MONEY INTO A BOTTOMLESS PIT, YOU ARE ACTUALLY PUMPING MONEY INTO IT, AND YOU ARE NOT SURE WHEN THIS WILL END.

THIS IS A HUGE RISK FOR THE PROJECT.

THE MOTIVATION HERE IS TO REALLY COMPLETE WHAT YOU STARTED.

NARRATOR: INSPIRED BY THE QUARRY HOTEL'S PROGRESS, ICE WORLD'S DESIGNERS REMAIN CONVINCED THAT DESPITE THE CHALLENGING TERRAIN, THE INDOOR SKI RESORT WILL BE FINISHED.

BUT THE 2018 DEADLINE FOR OPENING IS BEGINNING TO LOOK VERY UNLIKELY.

[SPEAKING MANDARIN] OF COURSE WE CAN FINISH IT.

WE CAN REALLY REALIZE IT.

IT'S NO PROBLEM, I THINK.

BECAUSE MANY UNEXPECTED SITE CONDITIONS WERE FOUND, AND WE NEED TO CONTINUE TO CHANGE OUR DESIGN TO ACCOMMODATE THAT.

SO I FEEL QUITE CONFIDENT THAT WE CAN FINISH THE WORK.

NARRATOR: MAY 2016.

IT'S THE END OF SPRING IN SOUTH CENTRAL CHINA, AND THE TEAM ARE HOPING FOR A CHANGE IN THE WEATHER AFTER ONE OF THE WETTEST WINTERS ON RECORD HAS CAUSED MAJOR DELAYS TO THE ICE WORLD SCHEDULE.

THE SITE'S GRAND OPENING IS STILL SLATED FOR 2018.

THAT'S JUST TWO YEARS AWAY.

AND THERE IS STILL NO SIGN OF AN ACTUAL BUILDING.

JUST OVER HALF THE 48 FOUNDATION COLUMNS ARE NOW IN PLACE, BUT THE BUILD JUST ISN'T MOVING FAST ENOUGH.

FOR SITE DIRECTOR LI XIAOGUANG.

THESE ARE WORRYING TIMES.

[SPEAKING MANDARIN] NARRATOR: LI MAY HAVE FAITH IN HIS 400 STRONG TEAM, BUT HIS IMMEDIATE CONCERN IS NOT WITH THEIR ABILITIES, BUT THEIR SAFETY.

THE NEAR-CONSTANT RAIN HAS TRIGGERED MASSIVE LANDSLIDES AT ANOTHER CONSTRUCTION SITE IN THE REGION, KILLING 35 CONSTRUCTION WORKERS.

[SPEAKING MANDARIN] NARRATOR: THE RECENT CATASTROPHE IS MAKING LI CONCERNED ABOUT THE SAFETY OF THE QUARRY ACCESS ROAD AND HIS WORKERS BELOW.

[SPEAKING MANDARIN] ♪ NARRATOR: FOR SAFETY, THE CONSTRUCTION TRAFFIC USING THE ACCESS ROAD IS REDUCED AND CAREFULLY MONITORED.

BUT THIS POSES YET ANOTHER PROBLEM FOR THE BUILD.

THE STRUCTURE HAS NOW REACHED A CRUCIAL POINT, CONSTRUCTION OF ICE WORLD'S GIANT 320,000 SQUARE FOOT FLOOR SLAB.

LOCATED 52 FEET ABOVE THE PIT, THE MAJORITY OF THE WEIGHT OF THE CONCRETE SLAB WILL BE SUPPORTED BY THE LEDGE CARVED OUT OF THE QUARRY, AS WELL AS THE FOUNDATION COLUMNS BELOW.

THE REST OF THE WEIGHT WILL BE TAKEN BY REINFORCED CONCRETE PLATFORMS BUILT INTO THE QUARRY WALLS.

TODAY, THE LARGEST OF THESE PLATFORMS, WHICH MUST CARRY THE HEAVIEST BEAM IN THE ENTIRE STRUCTURE, WILL BE POURED WITH CONCRETE.

[LI SPEAKING MANDARIN] NARRATOR: WITHOUT THIS BEAM, THE BUILD WILL GRIND TO A HALT, BUT IT NEEDS NEARLY 7,000 CUBIC FEET OF CONCRETE TO ENCASE THE REINFORCED STEEL BARS.

AND TO ENSURE IT DRIES AS ONE SOLID MASS WITH NO WEAKENING FLAWS, IT MUST BE POURED IN ONE CONTINUOUS CONTROLLED FLOW.

UNDER NORMAL CIRCUMSTANCES, THAT WOULD REQUIRE A CONSTANT CONVOY OF CEMENT MIXERS DELIVERING THEIR LOADS OVER A PERIOD OF ALMOST 24 HOURS.

IT'S TRICKY TO GET RIGHT EVEN UNDER OPTIMUM CONDITIONS.

BUT THE LETHAL MUD SLICK ACCESS ROAD INTO THE PIT MAKES THIS OPTION IMPOSSIBLE.

INSTEAD, THE ICE WORLD ENGINEERS HAVE COME UP WITH A UNIQUE SOLUTION.

[MAN SPEAKING MANDARIN] NARRATOR: PUMPING CONCRETE UP HUNDREDS OF FEET IS A TECHNIQUE THAT HAS BEEN PERFECTED OVER DECADES OF HIGH RISE CONSTRUCTION, BUT PUMPING CONCRETE DOWN IS FAR MORE COMPLEX.

IF THE SPEED OF THE CONCRETE FLOW IS NOT STRICTLY CONTROLLED, THE MIX SPLITS, COMPROMISING ITS FINAL STRENGTH.

THE KEY TO SOLVING THE PROBLEM IS SIMPLE BUT EFFECTIVE.

[SPEAKING MANDARIN] NARRATOR: FROM CEMENT MIXERS AT THE TOP OF THE QUARRY, THE CONCRETE IS FED INTO THE 260-FOOT CUSTOM-MADE CHUTE.

AS THE CONCRETE DESCENDS, IT PASSES THROUGH A SERIES OF CHANNELS AND GROOVES.

THESE REGULATE THE SPEED OF THE FLOW, KEEPING THE MIX CONSISTENT.

AT THE BOTTOM OF THE PIT, THE CONCRETE IS GIVEN ONE LAST MIX BEFORE BEING PUMPED BACK UP TO FILL THE SUPPORT BEAM.

[LI SPEAKING MANDARIN] NARRATOR: FINALLY, AFTER A TENSE 20 HOURS, THE LAST DROP OF CONCRETE IS POURED, AND A CRUCIAL PIECE OF THE SUPPORT STRUCTURE IS IN PLACE.

ONCE IT'S SET HARD, WORK CAN BEGIN CONSTRUCTING THE GIANT FLOOR PLATFORM THAT WILL PROVIDE THE SOLID BASE FOR THE INDOOR SKI RESORT.

IT'S JUNE 2017, ALMOST 3 YEARS AFTER WORK FIRST BEGAN ON CHANGSHA'S ABANDONED LIMESTONE QUARRY.

WHILE THE 320,000 SQUARE FOOT FLOOR PLATFORM OF ICE WORLD IS TAKING SHAPE, HIGH ABOVE, THE LUXURY HOTEL THAT WILL ACCOMMODATE VISITORS TO THE WORLD'S BIGGEST INDOOR SKI RESORT IS NOW NEARING COMPLETION.

ITS GLASS AND POLISHED STEEL EXTERIOR BELIES THE STATE OF THE REST OF THE BUILD.

THE DEADLINE FOR ICE WORLD'S SLATED GRAND OPENING IS NOW JUST A YEAR AWAY.

THE PROJECT'S INVESTORS WANT TO SEE RESULTS.

THE RESPONSIBILITY OF DRAGGING THE BUILD SCHEDULE BACK INTO LINE FALLS SQUARELY ON THE SHOULDERS OF ONE MAN, SITE MANAGER CAO PING.

[SPEAKING MANDARIN] NARRATOR: EVERY PIECE OF STEEL MUST BE WELDED INTO PLACE, AND THERE ARE NO SHORT CUTS.

[SPEAKING MANDARIN] NARRATOR: FOR THE PAST FEW MONTHS, THE NUMBER OF WORKERS ON SITE HAS TRIPLED TO 3,000, AND CONSTRUCTION HAS CONTINUED NIGHT AND DAY.

CAO PING IS LIVING AND BREATHING THE PROJECT 24/7.

AND THE PRESSURE OF THE PUNISHING WORKLOAD IS BEGINNING TO SHOW.

[SPEAKING MANDARIN] NARRATOR: TO ENSURE HE IS ALWAYS ON HAND, CAO HAS CONVERTED HIS OFFICE INTO A MAKESHIFT BEDROOM.

[CAO SPEAKING MANDARIN] NARRATOR: FOR CAO PING, THIS PROJECT HAS BECOME ALL CONSUMING.

HE HAS BEEN ON SITE FOR MOST OF HIS TWO-YEAR-OLD SON'S LIFE.

HE IS NOW DRIVEN TO NOT ONLY COMPLETE THE BUILD ON TIME, BUT TO CREATE A BUILDING THAT WILL MAKE HIS YOUNG FAMILY PROUD.

[SPEAKING MANDARIN] NARRATOR: OVER THE NEXT 6 MONTHS, CAO PING AND HIS TEAM WORK RELENTLESSLY... [CAO SPEAKING MANDARIN] NARRATOR: TO COMPLETE THE GIANT REINFORCED FLOOR PLATFORM.

TO GET TO THIS STAGE, THEY HAVE POURED OVER 12 MILLION SQUARE FEET OF CONCRETE AND INSTALLED OVER 80,000 TONS OF STEEL.

CAO PING HAS MET THE PUNISHING DEADLINE.

[SPEAKING MANDARIN] NARRATOR: FINALLY, THERE ARE SIGNS OF REAL PROGRESS IN THE QUARRY.

[MAN SHOUTS IN MANDARIN] NARRATOR: BUT ONCE AGAIN, THE STATE OF THE LIMESTONE, ALONG WITH YET MORE RAIN, IS CAUSING PROBLEMS FOR ANOTHER CRUCIAL PART OF THE BUILD.

ZHOU: THE MOST DIFFICULT PART OF THIS PROJECT IS THE CLOSE RELATION BETWEEN THE PIT WALL AND THE BUILDING STRUCTURE, BECAUSE THE PIT WALL ITSELF IS NOT STABLE ENOUGH, AND THERE ARE MANY LOAD TRANSFER REQUIREMENTS BETWEEN THE BUILDING AND THE PIT.

SO WE NEED TO FIND SOLUTIONS TO SOLVE THESE PROBLEMS.

NARRATOR: TO HELP SPREAD THE WEIGHT OF THE BUILDING AROUND THE ENTIRE STRUCTURE, THE TEAM IS INSTALLING A COMPLEX SYSTEM OF HORIZONTAL SUPPORTS.

15 ANGLED COLUMNS AND MORE THAN A THOUSAND STEEL ANCHORS RELY ON THE STRENGTH OF THE QUARRY WALLS.

BUT THEIR INSTALLATION IS NOT PROVING EASY.

JUST LIKE THE CRUMBLING BEDROCK, THE WALLS HAVE BEEN WEAKENED BY YEARS OF POLLUTION.

BUT HERE IT'S CREATED COUNTLESS UNDETECTED HOLLOW VOIDS.

[MAN SPEAKING MANDARIN] NARRATOR: AS SOON AS A HOLE IS DISCOVERED, IT MUST BE DRAINED, CLEANED OF SEDIMENT, AND FILLED WITH REINFORCED CONCRETE.

ONLY THEN CAN THE ANCHORS BE INSTALLED.

[ALL GRUNT] IT TAKES UNTIL JANUARY 2019 TO SHORE UP EVERY FOOT OF THE QUARRY WALLS.

THE ORIGINAL DEADLINE IS NOW A DISTANT MEMORY.

[MAN SHOUTS IN MANDARIN] BUT WORK IS AT LAST UNDERWAY ON ICE WORLD'S SUPERSTRUCTURE.

BUILT FROM 25,000 TONS OF HIGH STRENGTH STEEL BEAMS, THIS IS THE DRAMATIC CENTERPIECE THAT WILL HOUSE THE INDOOR SKI SLOPE.

TO PREVENT IT FROM RUSTING, THE ENTIRE STRUCTURE IS BEING ENCASED IN 14,000 CORROSION-RESISTANT ANODIZED ALUMINUM PLATES.

AND TO ALLOW IN THE NATURAL LIGHT, 35,000 SQUARE FEET OF GLASS IS BEING INSTALLED.

THE FUTURISTIC VISION THAT ONCE SEEMED LIKE AN IMPOSSIBLE DREAM IS FINALLY BECOMING A REALITY.

IT'S JANUARY 2020, 5 YEARS AFTER GROUNDWORK BEGAN IN THE LONG-ABANDONED LIMESTONE QUARRY, AND THE LANDSCAPE IS NOW VIRTUALLY UNRECOGNIZABLE.

THE 1,300-FOOT WIDE VOID IS NOW DOMINATED BY A SHIMMERING STEEL STRUCTURE BUILT TO HOUSE THE INDOOR SKI RESORT.

BELOW THE IMPOSING BUILDING, THE OLD QUARRY FLOOR IS ONCE AGAIN FILLED WITH WATER.

BUT THIS TIME IT HASN'T FLOODED IN.

NOW THE WATER LEVEL IS CAREFULLY CONTROLLED, CREATING A TRANQUIL BLUE LAGOON.

THE HAZARDOUS MUD-SLICKED ROAD THAT WAS THE ONLY ROUTE IN AND OUT OF THE QUARRY IS GONE...

REPLACED BY A SUSPENDED WALKWAY THAT WILL PROVIDE PUBLIC ACCESS TO THE LARGEST WINTER-THEMED PARK ON THE PLANET.

IN LESS THAN 5 MONTHS, THESE DOORS ARE SCHEDULED TO OPEN TO THE PUBLIC.

CAO PING'S JOB OF MASTERMINDING THE STRUCTURAL BUILD HAS FINISHED.

BUT NOW IT'S UP TO PROJECT MANAGER WONG DENGBIN TO FINISH THE JOB.

[SPEAKING MANDARIN] NARRATOR: FIRST ON THE LIST IS COMPLETING THE SUPER-SIZED ENTRANCE HALL, THE FIRST PORT OF CALL FOR ANY VISITOR TO ICE WORLD.

[SPEAKING MANDARIN] NARRATOR: AFTER PURCHASING THEIR TICKETS IN THE ENTRANCE FOYER, WINTER SPORTS ENTHUSIASTS WILL MAKE THEIR WAY DOWN INTO WHAT WAS 6 YEARS AGO THE MIDDLE OF THE OLD QUARRY.

NOW IT'S BEEN TRANSFORMED INTO THE MAIN SNOW DOME SUSPENDED OVER 300 FEET ABOVE THE LAKE.

400 DRESSING ROOMS, A VAST EQUIPMENT RENTAL FACILITY, AND EVEN A SUPERMARKET WILL CATER FOR THE THOUSANDS OF VISITORS THE INVESTORS ARE HOPING ICE WORLD WILL ATTRACT.

[WONG SPEAKING MANDARIN] NARRATOR: BUT BEFORE THE FIRST SKIERS CAN BE WELCOMED, MORE THAN 3 MILLION FEET OF CABLE NEEDS TO BE WIRED... OVER 3,800 SMOKE DETECTORS CONNECTED, AND MORE THAN 24,000 CERAMIC TILES LAID.

AS WORK TO COMPLETE THE CHANGING AREA RAMPS UP, INSIDE THE SNOW HALL, A LIFE-SIZED ALPINE VILLAGE IS NEARING COMPLETION...

ALONG WITH TRADITIONALLY DESIGNED SHOPS, RESTAURANTS, AND EVEN A LICENSED CHURCH FOR WINTER-THEMED WEDDINGS.

BUT THERE IS ONLY ONE KEY ELEMENT MISSING...

SNOW.

ALTHOUGH THE SNOWMAKING TECHNOLOGY HAS BEEN INSTALLED... RUNNING IT IS HUGELY EXPENSIVE, SO IT'S CRUCIAL ONCE IT'S TURNED ON, THE SNOW DOESN'T MELT.

TO ENSURE THAT DOESN'T HAPPEN, A VAST REFRIGERATION SYSTEM CONSISTING OF OVER 2,500 FEET OF PIPES AND MORE THAN A THOUSAND VALVES HAS BEEN INSTALLED UNDER THE FLOOR OF THE SNOW HALL.

AND EVERY INCH OF IT MUST BE CHECKED AND TESTED BEFORE THE FIRST SNOWFLAKE IS PRODUCED.

[SPEAKING MANDARIN] NARRATOR: IF THE SYSTEM ISN'T A COMPLETELY SEALED UNIT, IT WILL STRUGGLE TO MAINTAIN THE BELOW FREEZING TEMPERATURES NEEDED TO KEEP THE MANUFACTURED SNOW PRISTINE.

[SPEAKING MANDARIN] NARRATOR: UNTIL EVERY LENGTH OF PIPE AND EVERY SINGLE VALVE HAS BEEN INSPECTED AND APPROVED, THE BRAND-NEW SNOWMAKING EQUIPMENT MUST SIT IDLE AWAITING THE GREEN LIGHT TO START PRODUCING THE 400,000 CUBIC FEET OF SNOW NEEDED TO COVER THE VAST HALL.

[SPEAKING MANDARIN] NARRATOR: WITH JUST WEEKS TO GO UNTIL THE FIRST PAYING CUSTOMERS ARE DUE TO ARRIVE, A TEAM OF HUNDREDS IS WORKING AROUND THE CLOCK TO MAKE SURE EVERYTHING IS PERFECT FOR ICE WORLD'S LONG-AWAITED GRAND OPENING.

BUT THEN THE PROJECT IS HIT BY GLOBAL EVENTS BEYOND ANYONE'S CONTROL.

I'M DECLARING A PUBLIC HEALTH EMERGENCY OF INTERNATIONAL CONCERN OVER THE GLOBAL OUTBREAK OF NOVEL CORONAVIRUS.

NARRATOR: WORK ON ICE WORLD SHUTS DOWN AS CHINA GOES INTO LOCKDOWN AND THE REST OF THE WORLD FOLLOWS.

IT'S APRIL 2020.

AS CORONAVIRUS SPREADS TO EVERY CORNER OF THE WORLD, LOCKDOWN RESTRICTIONS IN CHINA BEGIN TO EASE.

IN CHANGSHA, THE ICE WORLD TEAM GETS BACK TO WORK.

THE LANDSCAPED WATER PARK PERCHED HIGH ABOVE THE QUARRY IS AT LAST TAKING SHAPE.

ONCE FINISHED, THOUSANDS OF GALLONS OF WATER WILL PROVIDE CRUCIAL COOLING FOR THE MAIN ATTRACTION BELOW.

WHILE INSIDE THE FUTURISTIC STRUCTURE ITSELF, THE SKI SLOPE IS AT LAST COVERED WITH THAT ALL-IMPORTANT SNOW.

AND A CABLE CAR SYSTEM IS NOW READY TO TRANSPORT WINTER SPORTS FANS TO THE TOP OF THE SKI PARK.

♪ [SPEAKING MANDARIN] NARRATOR: THE JOB OF MAKING SURE ICE WORLD'S SKI SEASON NEVER ENDS IS UP TO CHIEF SNOW ENGINEER XU JENU.

[SPEAKING MANDARIN] NARRATOR: MICROSCOPIC NOZZLES IN THE SNOW GUNS PUMP A MIXTURE OF CHILLED WATER AND COMPRESSED AIR INTO THE SUB-ZERO AIR.

THIS CREATES TINY ICE PARTICLES WHICH SNOW CRYSTALS THEN FORM AROUND, EVENTUALLY CREATING DRIFTS OF CRISP WHITE SNOW PERFECT FOR SKIING ON.

[SPEAKING MANDARIN] NARRATOR: 28 HIGH-POWERED COOLING FANS WORK 24 HOURS A DAY TO MAINTAIN AN AMBIENT AIR TEMPERATURE OF BETWEEN 23 AND 24 DEGREES.

WHILE HOURLY INSPECTIONS BELOW THE SNOW HALL ENSURE THE NOW LEAK-FREE REFRIGERATION SYSTEM STAYS THAT WAY.

[SPEAKING MANDARIN] NARRATOR: SO FAR, ALL THE NEW SYSTEMS ARE WORKING WELL.

DESPITE HIGH TEMPERATURES OUTSIDE, THE TEMPERATURE INSIDE HAS REMAINED WELL BELOW FREEZING.

AND THE SNOW GUNS ARE PROVING MORE THAN CAPABLE OF COVERING EVERY CORNER OF THE HALL IN THICK, POWDERY SNOW.

[SPEAKING MANDARIN] NARRATOR: 6 YEARS AFTER CONSTRUCTION BEGAN, AND DESPITE ALL THE SETBACKS THE ICE WORLD PROJECT HAS ENDURED, THE LARGEST WINTER-THEMED PARK ON THE PLANET IS ALMOST READY TO OPEN ITS DOORS TO THE PUBLIC.

[SPEAKING MANDARIN] NARRATOR: ABOVE THE MAIN STRUCTURE, THE 5-STAR LUXURY HOTEL WHERE VISITORS CAN STAY IN STYLE IS ALMOST READY FOR THE FIRST GUESTS TO ARRIVE.

[SPEAKING MANDARIN] NARRATOR: IT'S TAKEN A WORKFORCE OF THOUSANDS, BUT TOGETHER, THEY'VE MANAGED TO TURN THE ARCHITECTS' VISION INTO A REALITY.

[MAN SPEAKING MANDARIN] WANG: TO SOMEONE WHO'S NEVER SEEN THIS PROJECT, I WANT TO USE THE WORDS INCREDIBLE, SPECTACULAR, BECAUSE THERE ARE A LOT OF THINGS WE ARE DOING FOR THE FIRST TIME IN CHINA.

SO IT'S REALLY COOL.

AND ALSO I FEEL VERY PROUD OF THIS PROJECT.

NARRATOR: NOBODY EXPECTED THIS BUILD TO BE STRAIGHTFORWARD, AND IT WAS FAR FROM AN EASY RIDE.

THE POOR CONDITION OF THE LANDSCAPE CAUGHT EVERYONE BY SURPRISE.

BUT THE LONG-ABANDONED QUARRY HAS NOW BEEN SPECTACULARLY TRANSFORMED.

[SPEAKING MANDARIN] NARRATOR: WHEN THE DOORS TO ICE WORLD DO FINALLY OPEN, IT WILL HAVE THE CAPACITY TO ENTERTAIN 30,000 PEOPLE AT A TIME, ATTRACTING AN ESTIMATED 15 MILLION VISITORS A YEAR.

WHILE SOME WILL FIND THRILLS IN THE WATER PARK, SWIMMING ON THE ROOF IN 100-DEGREE HEAT, INSIDE, SUB-ZERO TEMPERATURES AND LAYERS OF THICK, POWDERY SNOW WILL ALLOW OTHERS TO ENJOY WINTER SPORTS ALL YEAR ROUND.

THE ICE WORLD TEAM HAS SUCCESSFULLY CREATED A TOURIST ATTRACTION QUITE UNLIKE ANYWHERE ELSE ON THE PLANET.