The immediate mountain area is a national park and a large swath of country around it a forest reserve. The two together are a UNESCO World Heritage Site.
Flora and fauna
Mount Kenya has a friendly climate.
Fees and permits
Single day: US$52 non-resident adult + $3 per car. 4-day package: US$255 for Adult Non Resident. US$65 per day for every additional day.
1 Climb Mt Kenya. This is typically a 5-day activity with a guide.
Day Hiking. Day hikes are somewhat hard to find. On the south side, Castle Forest Lodge (see sleep section) has a couple of short guided hiking options. On the north side, Camp Old Moses is a possible start and/or end point (though not necessarily worth the $52 entrance fee).
2 Ngare Ndare Forest. Ngare Ndare is known for its blue pools and waterfall - reserve ahead of time to ensure a guide is available to take you there (due to wild animals, you can't just go by yourself). It's either a 1 hour hike with an armed guard or a 4x4 drive with an unarmed guide from the 'office' under the canopy walk. There is also an elevated walkway (canopy walk) which is best done close to dawn/dusk when birds are active. $40pp/day + $10 mandatory guide.
1 Castle Forest Lodge. Beautiful lodge & campground outside of the park (read: no park fees). Cottages all have fireplaces. Chalet Montane has a hammock on the porch. Nature walks are offered for $7-10pp. Good place to relax for a couple of days. $170 for 2BR.