Mount Meru, Dormant stratovolcano in Arusha Region, Tanzania

This volcano reaches 4,562 meters (14,968 feet) in elevation and features a caldera measuring 3.5 kilometers (2.2 miles) across, containing several small cones and craters that indicate recurring volcanic activity.

Mount Meru lost much of its height when its summit collapsed about 7,800 years ago. Around 6,000 years ago a violent eruption, compared to Mount St. Helens in 1980, collapsed the crater's east wall and sent a flow of water, mud and stones eastward, creating the Momella Lakes. A smaller eruption in the 1880s left the Ashcone, a small cone inside the large crater; the last minor eruption was in 1910.

The mountain's name appears in colonial-era literature as Maeru, and the Maasai name given there is Dönjo Erok, "dark mountain". Its highest point has been called Socialist Peak since 1961, under Julius Nyerere. The Meru people live in the towns and villages near the slopes.

The climb via the Momella route from Momella Gate takes three days, with nights at Miriakamba Hut (2,514 m) and Saddle Hut (3,500 m). From Saddle Hut, climbers usually set off in the middle of the night, reaching Rhino Point (3,800 m) after an hour and the summit five hours later. No technical skills are needed, but sure-footedness is required.

Mountaineers use this ascent as preparation for Kilimanjaro expeditions, with Africa's highest peak visible from the summit on clear days.