The Glaswaldsee near the spa town of Bad Rippoldsau-Schapbach in the Central Black Forest in Germany lies in a cirque that is sunk into the steep eastern mountainside of the Lettstädter Höhe.

The tarn formed in a cirque that was carved from the bunter sandstone rock out by a glacier during the ice age.

Steep banks surround the lake which is up to 11 metres deep and has an area of about 3 hectares.

In 1655 Landgrave Frederick Rudolph of Fürstenberg-Stühlingen directed the Basle priest, Jakob Mentzinger, to prepare a map of his sovereign territory in the Kinzig valley.

To illustrate his approach to the national survey, Mentzinger recorded in the lower part of his map an enlarged view of the Glaswaldsee with the calculations made by him.