Just outside the village of Eresing, near the Ammersee, there is a small chapel and a fountain house where people would come wash themselves devoutly, especially the eyes. This spring is said to have healing powers, is dedicated to St. Ulrich of Augsburg, the patron saint of the diocese, who once allegedly rested here and caused the spring to flow forth. This is supposed to have occurred immediately after Ulrich’s returning from the Battle of Lechfeld (TL;DR version: FC Holy Roman Empire versus visiting Hungary, the Germans won.) Interestingly, the road near the fountain house and the chapel is also the old Roman road known today as the Via Raetia – so it’s possible that the spring was already known during Bavaria’s Roman period, and that travellers drew water from it. I have heard it suggested – although without evidence proffered – that it may have been a holy spring for the Romans as well. The gentleman in the video posted below (warning: it’s in “Boarisch“) claims that this spring’s water is soft, in contrast to the hard water found everywhere else in the area (and I can attest to that, out tap water is quite hard), and so locals fill up jugs of the stuff to brew their coffee with it.
The figure of St. Ulrich in the fountain house dates from the 15th century. In the 17th century the Court Margrave of Eresingen, Franz von Füll, subsidized the construction of the fountain house, the red marble basin, and the Ulrich chapel with hermitage.
The water is indeed surprisingly soft (low content of lime). Schondorf local artist Andreas Kloker (http://www.andreaskloker.de/) often serves it after his water painting performances.