Top tip - buy (500s) / take a photo of the map - the sign posts are numbered and clear, but the path color routes are difficult to follow.
What a find - this is a great place for a walk just outside the centre of Nairobi. The paths are easy to walk down and are suitable for walking, running or mountain biking. The waterfall is a must as part of your route. I went on a Friday and only saw 2 other people during the 4 hrs of walking.