Over the past 26 years, 16 expeditions have tried and failed to climb one of Pakistan's 8,000 meter peaks in winter. In 2011, Simone Moro, Denis Urubko and Cory Richards became the first. The journey nearly killed them.
Will Gadd and Tim Emmett discover the holy grail of ice climbing, Helmcken Falls, Canada where a cave features hundreds of feet of overhanging, barely climbable ice.
Sketchy' Andy Lewis takes the fledgling sport of slack-lining to new heights, performing aerial tricks like back-flips, BASEjumping off the line and even soloing highlines naked.
Speed alpinist Ueli Steck dances up faces in the Himalaya and the Alps, including his record-smashing ascent of The Eiger North Face. Ueli also teams up with fellow soloist Alex Honnold to break records on El Capitan.
