What Base Camp actually is
Everest Base Camp is a seasonal site on the Khumbu Glacier at 5,364 m, at the foot of the Khumbu Icefall, used each spring as a staging camp by climbing expeditions preparing their ascent of Everest's South Col route. No permanent structures exist here; the site is rebuilt on shifting glacier ice every climbing season.
What's actually there
During spring climbing season, dozens of expedition tents, kitchen shelters, and communications equipment spread across the rocky glacier surface, connected by makeshift paths marked with prayer flags. Outside the March to May climbing window, the site is largely empty ice and rock, visited only by trekkers on a day trip from Gorak Shep.
Trekkers versus climbers here
Trekkers on a standard EBC itinerary visit as a day trip from Gorak Shep (5,164 m) and do not overnight at Base Camp itself; climbing expeditions, by contrast, occupy the site for weeks at a time each spring, using it as their final staging point before pushing through the Khumbu Icefall toward the Western Cwm and South Col.
The marker cairn
A prominent rock cairn, decorated with prayer flags and often marked with expedition banners during climbing season, serves as the informal photo point most trekkers associate with reaching Base Camp, though its exact position shifts slightly year to year as the glacier beneath it moves.
No summit view from here
Base Camp itself has no view of Everest's summit, since Nuptse's west ridge blocks the sightline directly ahead; trekkers who want to see the summit pyramid make the separate pre-dawn climb to Kala Patthar (5,644 m) the following morning.
Origins: the early expedition camps
Everest's base camps predate the 1953 ascent. Sources place the 1952 Swiss expedition's base either at Gorak Shep or at the foot of the glacier. The British expedition led by Colonel John Hunt followed in 1953, leaving Kathmandu on 10-11 March and reaching Tengboche in late March, about two months before Edmund Hillary and Tenzing Norgay reached the summit on 29 May. Trekking tourism to the site came later. The camp's exact footprint keeps shifting, since it sits on moving glacier ice rather than fixed ground, which is one reason guidebooks and expedition reports don't always agree on its elevation to the metre.