Grüner See (Hundelshausen)

Grüner See is a lake in Hundelshausen, Hesse, Germany. At an elevation of 220 m, its surface area is ca. 5000 sqm.

Origin
The Green Lake, which is partially surrounded by steep slopes, was formed in 1940 when an abandoned open-cast mining pit from a gypsum quarry filled with groundwater, precipitation, and surface water. Its green color is due to its abundance of phytoplankton.