Schloss Mammertshofen

Schloss Mammertshofen is a medieval castle in Roggwil featuring a massive keep whose walls are approximately 3 meters thick, partially constructed from enormous glacial boulders exceeding 2 meters in length. The property is accessed by a stone bridge that replaced the original drawbridge and displays the substantial building methods of medieval times.

The castle was built around 1240 and initially served as a seat for Saint Gall marshals until their lineage ended in 1360. Afterward, the Schenk von Castell family took control and shaped its subsequent history.

The castle carries the name of its former owners and represents how medieval power was distributed across the region. Visitors can experience the structure today and sense how such fortifications shaped daily life and territorial control.

Access is via a sturdy stone bridge, with the entrance located at the southeast corner of the grounds. Visitors should note that this is a historic site and conditions may vary depending on the season.

The keep walls contain enormous glacial boulders weighing over 3 tons each, originating from the ice age and left largely unworked as part of the structure. This unusual building approach sets it apart from typical medieval fortifications.

Location: Roggwil

Location: Thurgau

Part of: list of cultural properties in Roggwil TG

Address: Mammertshofen 1–1.4, 9325 Roggwil TG

GPS coordinates: 47.49461,9.39794

Latest update: December 9, 2025 12:26