Eichener See

The lake that comes and goes. The reason for this is the background of shell limestone, which is soluble in water under certain conditions and is therefore permeated by numerous gaps and holes.

After heavy rains or after the snow melts it fills with water. It can take 8 to 160 days for the lake to disappear again.

The area is under conservation. Here lives the rare in Europe leaf tuberculosis Tanymastix lacunae (sounds like one of the Gauls from Asterix).

Source: Harenberg; Local nature 2018

The Eichener See (popularly, alemannisch Eiemer lake called) by oak trees in the district of Lörrach in Baden-Württemberg is a only occasionally (astatic) appearing karst lake.
The lake, which is only water-bearing when the groundwater level is high, lies in a hollow, a shell limestone karstic basin. He has no aboveground inflow, the outflow is partly underground and partly by evaporation.The Eichener lake is located in the Southern Black Forest Nature Park in the northeastern outskirts of the mountain range Dinkelberg between the nearby Schopfheimer district Eichen in the west, the municipality Hasel in the east-northeast and the core city of Wehr approximately in the southeast.
Geologically, it is a sinkhole, sometimes filled with water, in which groundwater comes to light especially after the snow melts or after prolonged periods of rain.(Source: Wikipedia)

Oak trees, sometimes by the lake. In the past you could still swim here.
Come and go as you please.
The festivities on May 1st are traditional here.