Ueli Steck returned to Nepal and the Annapurna south face in 2013 which he climbed solo, without oxygen, in one 28 hour alpine push, via a new route. The trip was his third attempt to climb the 8000 meter peak. Ueli Steck bouldering at Annapurna Basecamp. Ueli laying down exhausted after climbing Annapurna and then trying to boulder the next day.