When the name came up, is not known. Presumably, the Friendship Cave has long served as a place to live such. B. also the caves at Überlingen-Goldbach ("Heidenhöhlen").
It is proven that in 1688 a kind of house was already built in the rocks. Until 1785 there lived the last "Hüllelema" (= caveman), a day laborer (from Leutstetten) by the name of Hans Georg Sauter, who was in service with the princes of Fürstenberg. The fireplace is still visible today. Because of the poor condition of the apartment, he then built himself, as there was no place, a little further out a small hut.
Early construction
In the great snowmelt in 1802 there was also a risk of slipping and only then did he receive a building plot from the Fürstenbergers on Röhrenbacher Straße. He had already made the first entry in 1765! In the past there were already building worries ...
The rock of the Friendship Cave consists of so-called Nagelfluh, a glacial deposit material.