Very close to Lake Naivasha is Hell's Gate National Park. It's named that because of the amount of geothermal activity within the park.
We hiked along (and in) a streambed that runs through a canyon in the park. For at least a kilometer, we hiked barefoot and enjoyed the water that was warmed by hot springs.
On our way to the canyon, we drove past these amazing cliffs. (Click on that image to see an enlarged view.)
To see more, visit Jay's blog. If he hasn't posted about that yet, come back in a day or so.