Witch tower, Medieval fortified tower in Sarnen, Switzerland

The Witch Tower is a medieval stone structure in central Sarnen featuring thick walls, narrow windows, and multiple stories. The building dominates the town center and remains visible from many directions throughout the town.

Built around 1285 as the residence tower of the Lower Sarnen Castle for the knights Niklaus and Heinrich Kellner, who served the Murbach Abbey. In 1291 the Habsburgs acquired the castle; after the Kellners were driven out by 1308, the Landenburg family occupied it. By the 15th century it served as a prison, and in the 17th century it held accused witches, giving the tower its name.

The name Hexenturm only appears in records from 1861, long after the prison cell was demolished before 1798. It recalls the tower's use during the 17th-century witch-hunts, when accused witches were held here. The official name Archivturm, promoted in the 1980s, never caught on.

The tower is not open to the public, as it houses the Obwalden State Archives. It can be viewed from the outside; since 2009 a covered steel external staircase designed by Obwalden artist Kurt Sigrist has replaced the wooden stair. The tower stands in Sarnen's town centre.

The name Hexenturm is documented only since 1861, long after the last prison cell was demolished before 1798. The tower held accused witches during the 17th-century hunts, but the label came later. Since 2009 a covered steel outer staircase by Obwalden artist Kurt Sigrist replaces the wooden steps.