Remember that scene from the movie "Out of Africa" where Denys takes Karen on an amazing flight over Kenya? They fly along the rim of a crater, which is call Mount Longonot. Here's the scene.
Here I am standing on the rim of Longonot posing for a picture with some local kids, who were on a field trip to the crater.
This part of Kenya is already high altitude, and Longonot peaks at over 9,000 feet. I got altitude sickness on the hike (in part because I was carrying a backpack full of water bottles).
It was an experience of a lifetime, a magical day (despite the nausea and barfing).