Once acclimated to Base Camp, mountaineers begin climbing to camps higher and higher on the mountain and going back down to Base Camp between climbs. Sherpas establish these camps by pitching tents at each site prior to the mountaineers' first ascent. For many years the location of the camps differed annually, but over time certain spots became the traditional campsites for every climbing season.

Each camp is designated with a roman numeral —Camp I, Camp II, Camp III, and so on—with larger numbers being closer to the summit. On the north side, however, the first camp up Everest's slopes is called Advanced Base Camp, with Camp I coming after that. The reason for this is that once mountaineers have become fully acclimated to the altitude of the north base camp, they relocate their supplies higher up on the mountain...