This lake is a former calc quarry which after its closure it gradually filler up with water. The fresh water in the lake has a high concentration of calc, you will notice it once you enter the water. In the summer the surface temperature is high enough for quick swims but at the deepest point it is usually around 10C all year round. A 5mm thick wetsuit should be sufficient for about 1 hour longs diving sessions.
The deepest point is really close to the entry point and depending on the season, you can reach 11-12m. If you got to the bottom and it looks like you are in a hole, you have found the deepest point. Be prepared for a strong thermocline
You can get there by car or train+bike. There is usually sufficient space for parking.
Entry point coordinates: https://maps.app.goo.gl/t6pPgeBnyPRRK2979
Deepest point coordinates: https://maps.app.goo.gl/RurFePSgQiNkEiXt9
