By 1951 the location of the South Col was well known - it had been seen from the east in Tibet and photographed from the air - but it had never been possible to view its western side. There remained three main aspects of a route to Everest via the Western Cwm where the difficulties were unknown: the Khumbu Icefall, the climb up to the South Col, and the ascent to the final ridge it would also take longer do to the 6 ft of snow.