Blood Tower, Medieval tower in Red Quarter, Bern, Switzerland.

The Blood Tower sits at the northern edge of Bern's fortification wall with thick stone construction positioned alongside the Aare River. It served as part of the defensive system and controlled access to the city from this direction.

Built between 1468 and 1470, the Blood Tower was the northern closing element of the fourth western belt of Bern's medieval city fortifications. It was a half-round defensive tower, originally open to the east, measuring nine metres long, 8.7 metres wide and 8.3 metres to the roof base, with walls 2.1 metres thick. The artist Hans Rudolf Manuel first depicted it in 1549 in his view of the city of Bern.

The tower is part of the city's medieval fortification system and shows how Bern protected its boundaries. Visitors can see today how the town wall meets the river directly, using natural defenses.

The tower stands on the Langmauerweg path along the Aare, a short walk north from Bern's old town. The ground by the water is uneven and the low opening at the base faces the river, so watch your footing. The site is under cantonal protection and is best viewed from the outside.

From 1806 the Anatomical Institute used the tower to bleach skeletons, a practice that drew repeated complaints from the population. The name Blood Tower is first documented in 1732 by Johann Rudolf Gruner; earlier records call it Hexenthurm (1756) and Harzthurm (1783).