This natural monument is a spring funnel with a depth of around 12 m and is fed by several, almost inexhaustible springs. The water temperature is constant at 8 - 10 degrees in summer and winter, so this body of water remains free of ice even in winter. Even the research of geologists does not provide a complete explanation of this mystical body of water.
There is still a legend surrounding the "cool hole" phenomenon:
A farmer from Münster is said to have once driven a cart onto the field in the "Thal" area. When he started his journey home after work, his draft animals shied away in an inexplicable way. Out of control, his draft animals and cart headed down the mountain towards the "cool hole". The entire cart fell into the water. The strange thing about it, however, is that no one ever found the remains of the accident. The farmer, the cart and the draft animals remain missing to this day.
Source: Information board at the site