There's a lake that's made entirely of bat guano - Apparently.
Lake Natron, located in Tanzania, is a saltwater lake that's turned a deep red color due to the high concentration of bat guano. The lake's water is so alkaline that it can preserve dead animals, creating eerie, lifelike sculptures on its surface. The lake's unique chemistry is due to the presence of sodium carbonate, which is deposited by the surrounding volcanic activity and the guano of millions of bats that roost in the nearby caves. This phenomenon has been extensively studied and documented by geologists and photographers.