Freudenau castle ruin, Medieval castle ruin in Untersiggenthal, Switzerland

Freudenau is a medieval castle ruin situated on raised terrain above the Aare River near Untersiggenthal. The remaining stone walls and architectural fragments reveal the construction style of this fortification that once dominated the landscape.

The Habsburgs had a bridge built over the Aare below Freudenau around 1240, and the castle guarded that crossing. Decline began after 1300 when a ferry further upstream replaced the bridge. On 25 December 1351, the day before the Battle of Dättwil, a Zurich military campaign destroyed most of the complex; further parts fell to a major fire shortly after 1400, and the rest was abandoned.

The name Freudenau refers to the meadow by the ferry crossing below the Limmat mouth, where a medieval hamlet called Roost stood. The many cellars in the castle suggest it served as a transshipment point between river and land traffic. The Habsburgs had a bridge built here around 1240, and the old water routes from Bern, Lucerne and Zurich to Basel passed by.

Access to the ruin is reached through marked hiking trails that connect to the riverside path along the Aare and the Geissberg circuit route. The walk offers visitors a way to explore both the site and the surrounding landscape.

The many cellars in the ruin suggest the site served as a transshipment point between river and land traffic. The Habsburgs had a bridge built over the Aare here around 1240, shortly after the confluence of the Limmat, Reuss and Aare, where a single crossing was possible.