There's a lake that's a giant sinkhole - Apparently.
Lake Natron in Tanzania is a saltwater lake that's actually a massive sinkhole. Formed by the movement of tectonic plates, it's a depression in the Earth's surface that's been flooded by mineral-rich water from the nearby Engare Sero River. With a pH level of around 10.5, the lake is so alkaline that it can turn animals that die in it into stone-like structures, preserving their bodies in a process called permineralization. This phenomenon has been observed in numerous animal carcasses found in the lake.