The source of the Brigach springs from the cellar of the Hirzbauernhof farm in Brigach near St. Georgen. The spring was reclaimed in a place in front of the Hirzbauernhof. There is a group of stones at the source of the Brigach, which is now a copy of the original (the original is now in the town museum in St. Georgen). Three animals are carved into the stone, which presumably correspond to Celtic beliefs: a stag, a hare and a bird. The animals are surrounded by three heads, which are interpreted as gods. The stone can therefore be interpreted as a Celtic-Roman sanctuary. It is assumed that it refers to the goddess Abnoba. In the Celtic religion, Abnoba was a mother goddess. She personified the Black Forest, which in ancient times was known as Abnoba mons.