Sunburned cavers sounds like a contradiction, but on the opening sequence shoot for Journey into Amazing Caves, cavers and film crew were sunburned and sweltering in the 112 degree heat of the Little Colorado River Canyon, a tributary of the Grand Canyon.

High on a canyon wall -- 700 feet above a turquoise-colored river - film characters and cavers Nancy Aulenbach and Dr. Hazel Barton dangle on rope as they prepare to swing into an unexplored, ancient cave. Inside the cave, Aulenbach and Barton found geologic evidence that this cave was formed before the river cut the canyon, more than four million years ago. The river washed away sediment that had filled the limestone cave, exposing it to anyone who dared try to reach it.

Ah, yes, there's the rub: reaching it. MacGillivray Freeman Films worked as many days rigging for these shots as they did filming them. Director Steve Judson explains, "To film in five different locations within the canyon we had 30 people and 3-1/2 tons of gear - all of which had to be flown in and out by helicopter each day. We shot Space Cam aerials and photographed from a 20-foot truss rigged to the cliff face. Logistically, this was probably the most complex (3-day) shoot MacGillivray Freeman has ever accomplished."

The film crew and cavers approached the cave from the plateau above. A team of expert riggers devised a winch that lowered crew and equipment down the sheer cliff to the cave entrance. MFF trusted this venture to rigger and production manager Earl Wiggins whose last job was overseeing the safety of Tom Cruise in Mission Impossible 2.

Though Wiggins' rig is the best in the business, Aulenbach chose to rappel down the redwall cliff on her own. "I think I loved this shoot more than the others," confesses Aulenbach, who at 27 years old is adept at vertical caving. "I love being on rope," she adds, "and this was great experience for me to rappel down and then have to pendulum into a cave. The view was so spectacular!"

The canyon cave introduces audiences to the film's cavers and sets the stage for their adventures in the ice caves of Greenland and the underwater caves of the Yucatan. At each location, Dr. Barton studies the extremophiles - organisms that have adapted to the extreme environments for which they were named.

With an aim to take audiences on an adventure to explore unusual caves, an intrepid team of filmmakers from MacGillivray Freeman Films traveled to the northern-most country in the world, loaded three tons of gear into a helicopter, and flew thirty miles on to Greenland's ice sheet. They joined a French expedition of scientists and veteran ice cavers lead by Janot Lamberton. Lamberton, who has explored Greenland's ice caves since 1985, holds the world record for the deepest descent into an ice cave (203 meters or 665 feet). These blue caves, formed from glacial melt water that cuts through faults in the ice, are visually spectacular, but challenging to photograph.

The film crew worked two weeks on the glacier, braving cold snaps of 25 degrees below zero (F), and on one occasion, winds exceeding 100 miles per hour. They maneuvered camera, crew and cavers hundreds of feet down into treacherous vertical caves, and also filmed in horizontal caves just below the surface.

The team, lead by Director Steve Judson and Director of Photography Brad Ohlund -- the same pair who traveled to Mount Everest -- compared the remote Greenland shoot to Everest's filming conditions. Ohlund explains: "In both places our crews battled cold, ice and storms, but in Greenland, we were filming five-hundred feet below the surface: mountain climbing in reverse!" Dangers were ever-present. Ropes can freeze, trapping cavers and crew below the surface. Ice screws, holding crew or gear, can pop out from the pressure of the ten thousand foot-thick glacier. In the caves, ice shards can break away, falling like javelins toward cavers and crew. Thin spots on the ice can cause broken ankles, or worse, snow bridges can collapse, crushing anyone on or below them. Precious gear was almost lost when a snowmobile fell through ice. Film characters Nancy Aulenbach and Hazel Barton instinctively jumped into the waist-deep, freezing water to push the machine to safety. Their waterproof clothing was a welcomed after-thought.

Judson and Ohlund worked with Cameraman Gordon Brown, a newcomer to large-format filmmaking, but a veteran expedition cameraman in caves, and on mountains and rivers the world over. Brown created viscerally exciting shots with the same cold-ready "lightweight" camera that was used so successfully on Mount Everest. The "lightweight" camera weighs 25 pounds, compared to the 85-pound standard IMAX® camera. Viewers will feel as if they are dangling on a rope, hundreds of feet deep inside a chasm of shimmering blue ice. Adds Ohlund, "The Brown family - Gordon, Allison and Michael -along with Dave Schultz and Chris Blum, took on this location's challenges with enthusiasm and professional dedication. We couldn't have achieved the same level of success without them."

To film some of the world's little-known underwater caves, MacGillivray Freeman Films ventured to Mexico's Yucatan peninsula to explore the third longest (known) underwater cave, at Hidden Worlds Park. This more than 35-mile cave system stretches like a giant octopus beneath the jungle.

The many natural chambers of the cave were once dry. After the last ice age, the cave filled with water as the sea level rose. Golden draperies, crystalline soda straws, giant columns, stalactites and stalagmites now hang in the pristine, transparent water.

Producer Steve Judson signed on internationally known cave cinematographer Wes Skiles as the director of underwater photography, and award-winning, large-format underwater cinematographer Howard Hall. Cave diving is one of the most perilous sports on the planet and all twenty underwater crewmembers were aware of the challenges. "It is very easy to drift off into the dreamscape of the spectacular rooms and corridors we were filming," said Skiles. "We had to focus on exactly where we were, and exactly what our job was, so we wouldn't be lulled into the beauty without remembering the danger."

More than 350 people have drowned in underwater caves, where simple mistakes too often have fatal consequences. Getting lost or kicking up silt from the bottom of the cave, which can take hours to settle and clear, becomes a life-threatening situation when a diver's success is measured in breaths.

The most dangerous work on the shoot was accomplished by the grip and electric team. Once Skiles chose which locations and set-ups he required for each scene, the lighting crew often worked an entire day setting the lights, which were placed on weighted stands on the cavern floor. Skiles continues, "You just can't imagine how dark and big these places are. Hand-held lights, which is all they could use to see while setting up, were simply overpowered by the sheer darkness of the place--the darkness just swallowed the light!" The crew couldn't help but kick up silt as they worked. Often the silting and visibility became so bad, the crew had to feel their way out of the cavern by following the light cable back out. During filming, the powerful 70-pound lights had to be taken apart and charged at the surface for every 20 minutes they were used.

Producers Greg MacGillivray, Alec Lorimore and Steve Judson were thrilled with the footage, which included some stunning topside shots directed by Tom Cowan (Africa's Elephant Kingdom) and photographed by MFF's Brad Ohlund. Describing the overall shoot, Judson says, "We were aiming to give the Yucatán sequence a visceral, adventurous feel, and the footage has that in spades. Some of the shots are pure magic."