After World War II, with Tibet closing its borders and Nepal becoming considerably more open, Mount Everest reconnaissance from Nepal became possible for the first time culminating in the successful ascent of 1953. In 1950 there was a highly informal trek to what was to become Everest Base Camp and photographs were taken of a possible route ahead. Next year the 1951 British Mount Everest reconnaissance expedition reconnoitred various possible routes to Mount Everest from the south and the only one they considered feasible was the one via the Khumbu Icefall, Western Cwm and South Col. In 1952, while the Swiss were making an attempt on the summit that nearly succeeded; the 1952 British Cho Oyu expedition practised high-altitude Himalayan techniques on Cho Oyu, nearby to the west.