In the middle of Althegnenberg, in the immediate vicinity of the parish church, there is a "mountain chapel" that stands on an artificially raised mountain.
This mountain is a fairly regular truncated cone. It is the tower hill that supported the small Hegnenberg castle in the 11th and 12th centuries. This castle was a residential tower made of wood or stone.
Such moths were typical castles of the Salier period. These tower buildings are without exception to be assigned to the lower nobility or the up-and-coming class of the ministerials.
The Hegnenbergs were those ministerials who were able to expand their political influence and finally founded the Hofmark Hegnenberg. This domain lasted for over 500 years.
In the 13th century, the Hegnenbergers built a new castle 4 km to the west, the Neu- or Hofhegnenberg, which more appropriately represented the high status of the family. The old moth lost its importance and began to deteriorate. The name of the village later changed to the current name: "Althegnenberg".
The mountain chapel "St. Maria" was built on the castle hill in 1676. It was modeled after the Bregenz master builder Jobst Moosprucker as an octagonal central building of the Altöttinger Gnadenkapelle. St. Maria developed into a regional pilgrimage, so that a long house was added about 100 years after it was built. Today this chapel is used as a place of worship by the Evangelical Lutheran parish. A very forgiving nod of history when you consider that only a generation before the chapel was built, Catholics and prostestants fought in the most terrible way for 30 years.
The small town of Althegnenberg has even more visible buildings from the Middle Ages, namely the listed old forge and the former farmyard of the castle.
In 1995 the moat with the bridge and the adjoining Schmiedegasse were restored.