Altenfels Castle (Ruin) (Rösenbeck)

Altenfels Castle (also known as Burg Altenfils) is a lost castle near Brilon-Rösenbeck in the Hochsauerland district in the east of North Rhine-Westphalia, Germany.

On the 486 m high Altenfels mountain, which drops steeply by 150 m to the south, there were two castle complexes from the High Middle Ages. The remains of the castle on the western summit could only be investigated in 1968 through an emergency excavation before they were destroyed by quarrying. In contrast, the remains of the eastern castle were excavated, secured, and made accessible.

Little is known about the history of the eastern castle. It is estimated to have existed from about 1100 until the third quarter of the 12th century and was destroyed by fire. The main components were two towers, possibly used for residential purposes. The area between them was secured by ramparts and moats. There are no indications of further construction on the site.

Only for the western castle are there some indications. According to archaeological findings, the western castle was built in the second half of the 11th century. It was first mentioned in 1144 in a property register of Count Siegfried IV of Boyneburg and Homburg. In 1202, it appeared in the partition treaty of the sons of Henry the Lion. Later it fell into disrepair and came into the possession of the Archbishops of Cologne. Siegfried von Westerburg assured the citizens of the city of Brilon in 1294 that they would have nothing to fear from the restored complex. Since they helped with the construction of the castle, they were rather promised protection. A bishop's castle garrison was last mentioned in 1326. According to archaeological evidence, the western castle was destroyed in the 14th century.