Altenburg Castle

The Altenburg was a medieval lowland castle (motte) on the outskirts of Blankenheimerdorf, a district of Blankenheim in North Rhine-Westphalia.

The vanished castle was located in a swampy river valley. In it rises a rock block up to 25 m high and about 100 m long. The rock was probably prepared for a castle as early as the 10th century, as the sides have been artificially steepened. The Altenburg, which was originally intended to protect Blankenheim, was demonstrably inhabited from the 13th to the 15th century. A ministerial family is documented until the 17th century.

The moat is still visible in the eastern part of the complex. The actual castle mound is now covered with rubble. The foundations of a large building suggest a fortified palas. A tower would have stood on the higher elevation. This main castle was surrounded by a curtain wall, which has almost completely collapsed.

Since the castle, although considered impregnable, could not be expanded, the noble lords built a new castle in Blankenheim.