Lake Nakuru is a shallow alkaline lake lying on the floor of the eastern Rift. At no time this century has the lake depth exceeded twelve feet. Eburru mountain _ a dormant volcano _ rises in the background. The lake is an internationally accredited Ramsar site because of its rich bird life. A quarter of the world's lesser flamingo population may be seen hugging its mineral-stained shores when conditions are right for the growth of blue-green algae (Spirulina platensis) upon which the birds feed.