This undated photograph shows unidentified mountaineers as they walk past the Hillary Step whilst pushing for the summit of Mount Everest as they climb the south face from Nepal. Nepal marked 60 years since the first ascent of Everest May 29, celebrating the summiteers whose success has bred an industry that many climbers now fear is ruining the world's highest peak. AFP PHOTO/Tshering SHERPA (Photo credit should read TSHERING SHERPA/AFP via Getty Images)
