Gelnhausen lies to the south of the Vogelsberg Hills. Beneath the red sandstone, there is a layer of shale containing many water-bearing channels which come to the surface where the shale is exposed on the slopes.

Fresh water is thus plentifully available – an essential requirement for any settlement. The good supply of water was surely a factor in Emperor Frederick I “Barbarossa’s” decision to establish a town and palatinate here.

Many homes had their own wells. 68 wells were counted in a survey, but occasionally further ones are discovered during building work, most recently in the Breydenbach cellar on Untermarkt, the Lower Market Place.

The public wells in and around the town were supervised by officially nominated citizens. The pollution of wells was a criminal offence. For example, in the regulations of a city in Saxony dated 1569, a fine is imposed for washing in public wells or contaminating them in any other way.