Balm ruins

Balm ruins are the remains of a fortified dwelling built into a cave at the foot of the Balmfluh cliff in the Swiss Jura, in the municipality of Balm bei Günsberg, Canton of Solothurn. It is the only cave stronghold in the canton and one of just a few in Switzerland. The site is listed as a Swiss heritage site of national significance.

What are the Balm ruins?

The castle was set inside a large natural rock recess that gave its inhabitants shelter from the weather and gave the walls something to lean on. German speakers call this type of building a Grottenburg, a "grotto castle". The builders did not need to raise a full defensive structure, because the rock covered the buildings from above and behind.

What did the castle look like?

The complex had three parts. The lower section held barns and tents, a middle section linked the levels, and the stronghold itself occupied the big cave. The outer wall was 2.4 metres thick, with two doorways and narrow windows. Holes cut into the rock show where the beams of a simple two-storey timber structure rested inside.

Who held Balm?

The Freiherren (barons) von Balm are usually considered the builders, and the place carries their name. Sources date the castle to about the middle of the 11th century. In 1308 the family lost the lordship and the castle, which passed as an imperial fief to Count Otto of Strassberg. In 1320 the knight Pantaleon von Gebstrass, an official from Solothurn, took Balm over as a pledge. Count Rudolf III of Nidau redeemed it in 1327.

Decline and excavation

During the 14th century the castle fell into disrepair and became a ruin. Excavations in 1939 and 1941 showed that the cave had been used since very early times, and the Historical Dictionary of Switzerland notes habitation from the Neolithic onward. Renovation began in 1939 and finished in 1941. Sources disagree on the exact period of occupation: one listing gives roughly 1000 to 1400, while another places the fortifications between the 11th and 15th centuries.

Practical information

• Location: foot of the Balmfluh, Jura, Canton of Solothurn, about 47.256 N, 7.555 E.
• Entry: according to a 2022 listing, the ruin is free to visit with no fixed opening hours.
• Best for: fans of medieval architecture, Jura scenery and short countryside outings.

Frequently asked questions

Is there an entrance fee for the Balm ruins? According to a 2022 listing, no. The site is freely accessible and has no set opening restrictions.

When was the castle built? Sources point to around the mid-11th century, with use continuing into the 14th and 15th centuries.

Why is the site special? It is the only cave stronghold in Solothurn and one of very few in Switzerland, and it is a heritage site of national significance.

Who owned the castle? Most likely the barons von Balm at first, then after 1308 Count Otto of Strassberg, the knight Pantaleon von Gebstrass and Count Rudolf III of Nidau.