This detailed photograph taken from the International Space Station highlights the northern approach to Mount Everest from Tibet. Known as the northeast ridge route, climbers travel along the East Rongbuk Glacier (top right) to camp at the base of Changtse Mountain. From this point at approximately 6,100 m (20,000 ft) above sea level, the North Col – a sharp-edged pass carved by glaciers, center – is ascended to reach a series of progressively higher camps along the North Face of Everest, culminating in Camp VI at 8,230 m (27,000 ft) above sea level. Climbers make their final push to the summit (not visible, just off the bottom edge of the image) from this altitude. Image courtesy of NASA.