Annelie Pompe embarks on a mission to both scale the heights of Mount Everest and freedive to the lowest recorded depth of the ocean, an achievement that would make her the record-holder for a woman who has reached the greatest height and depth.

Nearly 60 years to the day after the first ascent up Mount Everest, Russian mountaineer Valery Rozov attempts to fly off the north face of Mount Everest and achieve the world's highest BASE jump ever at 7,220m above sea level.

Survivalist Joe Vogel dares the crossing of the most unforgiving desert on earth: 240km across Bolivia's vast salt lake known as the Salar de Uyuni. After an aborted attempt with a partner a year ago, Vogel makes the perilous journey solo.

Sebastian Copeland and partner Eric McNair-Landry cross 2,300km of the Greenland ice sheet. Braving a week-long blizzard in a small tent, the duo set a world record for the longest distance travelled on skis and kites in 24 hours.

Australian hang-glider Jonny Durand sets out to perform loop-the-loop aerobatics on the leading edge of the so-called sky tsunami, Morning Glory, a rare, 2km-high tube-cloud phenomenon that clings precariously low to the ground.

Eighty metres of mystery lies between two giant cave systems deep beneath the New Zealand wilderness. If Troy Watson and Kieran McKay can connect the Nettlebed and Stormy Pot systems, the find will be the biggest cave in the southern hemisphere.

Ten skiers, filmmakers, writers, photographers, and sailors set off on a journey to ski the Antarctic Peninsula. Chris Davenport, Stian Hagen and Andrea Binning hike and ski new peaks in one of the world’s last, largely unexplored regions.