El Misti, the symmetrical 5,822-metre volcano that looms over Arequipa from the north-east, is the city's natural emblem. From almost anywhere in the centre you can see it framed at the end of a street. Despite the conical perfection of its silhouette it is still classified as active — the last eruption was in 1985 — and the smoke trails from its crater are visible on a clear day.
Climbing El Misti is one of the more accessible high-altitude peaks in South America: no technical equipment required, but real altitude (you sleep at around 4,800 metres) and a brutally long summit day. Most agencies in town offer a two-day guided ascent for around 200–300 US dollars. You should be properly acclimatised before attempting it — spend several days in Cuzco, Puno, or Arequipa first.