Hasenburg, Medieval castle ruins near Buhla, Germany

Hasenburg is a castle ruin set on a raised plateau in the German village of Buhla. What remains today includes stretches of wall, defensive ditches, and parts of the original layout that give a clear picture of how the site was once arranged.

The site was already settled during the Bronze Age before it became an imperial castle under Emperor Heinrich IV around 1070. That shift turned a prehistoric stronghold into a medieval seat of power.

The name Asenberg, recorded around 1070/74, refers to the Norse gods (Asen), and a pagan sanctuary was later believed to have stood on the mountain. In the 16th century the site belonged to the Counts of Hohnstein, who enfeoffed the Lords of Bültzingslöwen with the Hasenburg and its appurtenances. The castle area is now a protected archaeological monument used for agriculture and forestry, and visitors can enter freely.

The site is open to visitors, with the main access point at the southern end of the plateau. The eastern and northwestern slopes drop off sharply, so it is best to stay on the marked paths.

The site was already a fortified hilltop settlement in the Hallstatt period, more than 4000 years ago, and was used again and again by later settlers. Excavations since the 1960s uncovered a 6 × 2 m chamber gate at the southern access and a bronze belt buckle plate with two blue and red enamelled lion heads, dated to the 11th century.