Kilimanjaro

Three volcanic cones — Kibo, Mawenzi and Shira — of which only Kibo still carries ice. Uhuru Peak, on Kibo's rim, stands at 5,895 metres, and the climb passes through something close to a continental cross-section: cultivated foothills, then rainforest, then heath and moorland, then high alpine desert, then the ice.

The summit is a walk rather than a climb, requiring no technical skill, and that is precisely why it is underestimated. The determining factor is acclimatisation, not fitness. Roughly half of those attempting it on a five-day itinerary fail to reach the top; on eight days most succeed. There is no way to buy past the time your body needs between three and four thousand metres.

The mountain also runs on labour that is easy not to see. A climb employs guides, cooks and porters — often more than three staff per climber. The Kilimanjaro Porters Assistance Project publishes standards on wages, load limits and equipment because those things were routinely neglected. Operators meeting those standards cost more, and the difference goes to the people carrying the loads.