Zähringen castle

The ruins of Zähringen castle is what remains of the ancestral seat  of the Zähringer. It is one of several castles and towns that the Zähringens built in South Germany and Switzerland (including: Freiburg i. Breisgau, Villingen, Neuenburg, Fribourg-Freiburg i. Üechtland, Bern, Thun, Rheinfelden, Murten)