The bathing lake known as the "pit" is not a natural body of water– lignite was mined here between 1908 and 1921. After the plant had to close in 1924, the pit filled with water, was used as a reservoir for it, and always (illegally) also as a bathing place. Since 1974, the banks have been flattened and planted - and Darmstadt has one more open-air swimming pool!

Today, the "pit" is still a popular destination for young and old, for swimming, taking a walk, oder fishing. Situated away from the city, it can be reached by bike or by taking the FU bus line.