Grimmenstein Castle Ruin

Grimmenstein Castle Ruin (Burgruine Grimmenstein) sits on a wooded slope above St. Margrethen, in the Rhine Valley (Rheintal) of the canton of St. Gallen, in Switzerland's far north-east. Of this medieval stronghold, the main survivor is a tall section of a massive residential tower. Entry is free and the site is open at all times.

What is the history of Grimmenstein Castle?

The castle was built before the middle of the 13th century for Konrad von Falkenstein, a vassal of the Abbey of St. Gallen. It stood on a sandstone ridge above the old chapel of St. Margaret. The family later took its name from the castle and became known as the Grimmensteins. When the line died out in 1315, the castle passed to the barons of Enne.

The following century was turbulent. The stronghold was captured in a feud in 1361 and partly destroyed during the Appenzell Wars in 1405. The Enne family rebuilt it in 1412, but in 1416 it was razed and never restored.

What can you see today?

The most striking remnant is the high wall of an exceptionally strong residential tower. A cistern cut into the bedrock also survives, which once supplied the garrison with water. The municipality of St. Margrethen owns the ruin and carried out a thorough conservation of the masonry in 2023-2024. An information board on site tells the story, and in 2025 the cantonal archaeologists and the Swiss Castle Association devoted a dedicated publication to the site.

How do you get to the ruin?

The easiest start is Walzenhausen, about 500 metres higher up. From St. Gallen, take the train to Rheineck, then the Rheineck-Walzenhausen mountain railway. From the marked trail it is roughly a 15-minute walk to the ruin.

The Walzenhausen-Berneck stage of the Rheintaler Höhenweg passes the castle. It runs about 8.4 km and takes around 2.5 hours, with the Meldegg restaurant along the way. A longer loop from Walzenhausen, about 9.7 km, links the ruin with Grimmenstein Monastery.

When is the best time to visit?

There are no opening hours, so you can visit all year. Late spring to autumn offers the driest paths. On a clear day the area gives views toward Lake Constance and the Vorarlberg Alps. Wear sturdy shoes, as the approach follows forest paths.

Frequently asked questions

Is there an entrance fee for Grimmenstein ruin? No. Entry is free and there are no set visiting hours.

When was the castle destroyed? It was razed in 1416. It had been damaged in 1405 during the Appenzell Wars and rebuilt in 1412.

How do I get there from St. Gallen? Take the train to Rheineck, then the mountain railway to Walzenhausen. From there a trail leads to the ruin in about 15 minutes.

What remains of the castle? A tall wall section of the residential tower and a cistern hewn from the rock.