Lake Retba, Senegal, East Africa. It's named for its pink waters, caused by Dunaliella salina algae in the water that produce a red pigment that uses sunlight to create more energy, turning the waters pink. The color is particularly visible during the dry season. The lake is also known for its high salt content, which, like that of the Dead Sea, allows people to float easily.
The Lakes of Mount Kelimutu, Indonesia are considered to be the resting place for departed souls, the lakes are locally referred to as "the lake of evil spirits". All 3 lakes change color from blue to green to black or red unpredictably.
Reflective salt flats in Bolivia.