Bucksturm, Medieval watchtower in Osnabrück, Germany

The Bucksturm is a medieval defensive tower in the old town of Osnabrück, built with thick stone walls and narrow openings designed for handheld weapons. It stands along Bocksmauer street and is one of the surviving sections of the city's former fortification ring.

Built at the start of the 13th century as a watchtower on the city wall between Heger Tor and Natruper Tor, the Bucksturm held Osnabrück's city prison in the Middle Ages. Prisoners included Count Simon of Lippe in the early 14th century and Johann von Hoya, confined from 1441 to 1448 in the Johanniskasten on the second floor. Six Anabaptist preachers from Münster were held here before their transfer to Iburg on 18/19 October 1534. In the 16th and 17th centuries it also served as a torture chamber during witch hunts. Originally 28 metres tall, it lost about ten metres in 1805 due to dilapidation.

The Bucksturm is closely associated with the witch trials of the 16th and 17th centuries, when it was used to hold people who had been condemned. Passing by today, visitors see a plain stone tower that gives little outward sign of what once took place inside.

The interior is not open to visitors, but the exterior and the 1922 war memorial beside it are clearly visible from Bocksmauer street. Visiting during daylight makes it easier to take in the details of the stonework.

On the second floor there once stood a solid oak chest called the Johanniskasten, which was used as a prison cell. The robber knight Johann von Hoya was held inside it from 1441 to 1448.