The Meke Gölü is a lake inside the crater of a volcano. In the center is another volcano from a later eruption. The water of the lake contains a high concentration of sulfur dioxide and salt. The red color is probably from the microorganisms which are able to survive in this liquid. The smell here on the level of the lake is awful, like rotten eggs. But as soon as you are a few meters higher, up the central volcano, the air is full of the flowers perfume which are in blossom now in spring.