St. Ursanne Castle (Ruin)

The origins of St. Ursanne Castle date back, possibly to a Roman observation post that secured communication routes between Vesontio and Augusta Rauracorum. After its destruction by Vandals and other invaders in the early 5th century, the remains served as the foundation for medieval fortifications. A noble family from St-Ursanne, likely descendants of the Gliers, inhabited the castle in the 12th and 13th centuries. In the 14th century, the complex passed into the possession of the Bishop of Basel. The first documented mention of the castle occurred in 1333. The castle was the scene of numerous pledges and military conflicts, especially during the Thirty Years' War. In May 1634, it was occupied by French troops, leading to a massacre of the garrison. After further sieges and conquests by French and Imperial troops, it returned to the possession of the Bishop of Basel in 1648. In 1796, the castle was sold as national property and subsequently demolished, its stones used for the construction of a cotton mill, which fell victim to a fire in 1852.

The St. Ursanne ruin is located in the town of St-Ursanne in the district of Porrentruy, Canton Jura, Switzerland, at an altitude of approx. 521 m above sea level.

Today, only a few scrub-covered walls and traces of ditches remain of the castle on an extensive platform. The ruin is accessible to visitors.