Eichholzmaar

This lake is no ordinary hole in the ground. It is a volcanic crater created when magma from below got to the water table and exploded in a flash of heat and steam. The crater has a low rim, like a meteor crater, most of the way round. There is also a local spring about 500m away that trickled down to fill the hole making this lake. However, the water is saturated in CO2, Iron and Manganese, so whilst it provides a healthy growing environment for the plants, the water can be quite anoxic (particularly at the lake bottom).

We tested the water at another of the local springs (see extra)