Salt-loving algae gives a red color to the hyper-saline waters of Lake Natron in the Great Rift Valley on the border between Tanzania and Kenya. The lake has an unusual mineral content that is leached from the surrounding volcanoes. The temperatures in the salty mud can reach 50 degrees Celsius (120 degrees Fahrenheit), and depending on rainfall, the alkalinity can reach a pH of 9 to 10.5 (almost as alkaline as straight ammonia).