He deliberately chose the location at a former Celtic-Romanic place of worship, whose existence was proven by several finds in the 17th century. It was a sanctuary of the Celtic Goddess Rosmerta and later of the Roman God Mercury. Altogether, five benediction inscriptions are known. At different occasions, new wall fragments were excavated. Hence, it is assumed that small buildings stood here on “Zimmethöhe”, which may have been lodgings for the pilgrims with stables and barns.