Lake Natron is a salt or alkaline lake located in north Ngorongoro District of Arusha Region in Tanzania at the border with Kenya. It is in the Gregory Rift, which is the eastern branch of the East African Rift. The lake is within the Lake Natron Basin, a Ramsar Site wetland of international significance. It is the only regular breeding area for Africa's lesser flamingoes, although this habitat is not protected and is under threat from planned development projects.