To the western side of Tsavo West is the Chyulu Hills National Park. Chyulu Hills lie parallel to the Nairobi Mombasa road and is an example of recent volcano activity. Tropical plants, elephant, lion, buffalo, kongoni, and giraffe among other animals live here. Umanyi springs is a home for crocodiles and different species of birds. It is under these hills that among the longest caves in the world exist. The area is scarcely populated with no permanent water supply.