Château du Hugstein, Medieval castle ruins between Buhl and Guebwiller, France

Château du Hugstein is a ruined castle on the border of Buhl and Guebwiller, built of rough reddish-brown masonry. Its taller left tower is partly hidden by vegetation, while the right section has a large open archway, a rectangular window opening, and a row of small arched recesses near its broken top. The cylindrical keep, 10 m in diameter, is rare in Alsace.

The fortress was founded in 1227 by Hugo de Rothenburg and served the Murbach Abbey as a defensive stronghold. Later in the medieval period it became a place of confinement before eventually falling into disuse.

The castle's name comes from Hugo de Rothenbourg, the abbot prince of Murbach who built it in 1227. In the early 17th century it served as a prison for Lutherans and alleged witches, some of whom were burned in front of the walls. The Gothic keystone of the chapel vault, carved with an Easter lamb, is now kept at the Musée Théodore Deck in Guebwiller.

Access is free and unguided, and the ruins stand on the communal boundary between Buhl and Guebwiller above the entrance to the Florival valley. The walls are unconsolidated in places, and the keep lost its upper section when the site was quarried, so keep to the paths and watch for falling masonry.

A richly decorated Gothic keystone from the chapel featuring an Easter lamb carving was brought to the Florival Museum in Guebwiller. This find reveals the artistic details that once adorned the structure.