Mount Kenya is an extinct stratovolcano that was once perhaps 7000 m high and has eroded to a set of jagged rock spires. It sits almost exactly on the equator and still carries small glaciers, though they have lost more than 90 percent of their area since 1900 and are expected to vanish within a couple of decades.
Three summits
Batian at 5199 m and Nelion at 5188 m are rock climbs requiring technical skill and equipment; the standard route on Nelion is a long day of graded climbing. Point Lenana, 4985 m, is a walk, and it is what almost everyone means when they say they climbed Mount Kenya. Reaching it still puts you above almost everything in Africa.
Routes
Sirimon approaches from the north-west, is the driest and has the best acclimatisation profile, usually four or five days. Chogoria from the east is widely considered the most beautiful, passing Lake Michaelson and the Gorges Valley, and is often combined with Sirimon as an up-and-over traverse. Naro Moru from the west is the fastest and includes the notorious vertical bog; it has the highest failure rate because people ascend too quickly.
Altitude
Point Lenana is only 900 m lower than Kilimanjaro summit and the same rules apply. Three days is too fast for most people; four or five is sensible. The advantage over Kilimanjaro is that Mount Kenya has better acclimatisation terrain, with the option of sleeping at intermediate camps and day-walking higher.
The vegetation
The climb passes through rainforest, bamboo, and then the extraordinary afro-alpine zone of giant lobelias and groundsels that grow several metres tall and exist only on East African mountains. Rock hyrax are everywhere at the huts and will go through unattended bags.
Practicalities
Park fees are around 60 US dollars per person per day, plus guide and porter costs. A guide is required. Total cost for a four-day trek is typically 500 to 900 US dollars, considerably less than Kilimanjaro. The best months are January and February and again August and September; the long rains from March to May make the routes miserable.
Below the mountain
The Mount Kenya region has excellent lodges on the forested lower slopes, and Ol Pejeta and Lewa conservancies lie on the plains to the north, which makes combining mountain and safari straightforward.