The Blue pot (Blautopf) in Blaubeuren is a special natural experience. It is fed by a karst spring, the second richest in water in Germany. As the name suggests, the Blue pot Blaubeuren is characterised by a striking blue colouring of the water, the intensity of which can turn to a blue-green with an almost magical effect depending on the incidence of light. Around the Blautopf, there is an extensive, branched cave system. The Blautopf has also inspired sagas and legends time and again. Eduard Mörike tells of the “beautiful Lau”, a water mermaid who learns to laugh again at the Blue pot. According to another legend, the Blue pot was considered bottomless. If one tried to determine the depth with a plumb bob, this was prevented by a mermaid who stole the weight of the plumb bob. A stone sculpture on the shore commemorates her.