"Lake Natron in Tanzania is one of the most serene lakes in Africa, but it’s also the source of some of the most phantasmagorical photographs ever captured - images that look as though living animals had instantly turned to stone.
The alkaline water in Lake Natron has a pH as high as 10.5 and is so caustic it can burn the skin and eyes of animals that aren’t adapted to it. The water’s alkalinity comes from the sodium carbonate and other minerals that flow into the lake from the surrounding hills. And deposits of sodium carbonate - which was once used in Egyptian mummification - also acts as a fantastic type of preservative for those animals unlucky enough to die in the waters of Lake Natron.”
Read more here.