Altdahn Castle, Velburg

The castle occupies the two largest eastern rock outcrops on the Dahn ridge, arranged roughly east-northeast to west-southwest along a stretch of about one hundred metres. Builders used the natural sandstone outcrops as the primary structural base and set stone masonry directly against the rock. On surviving wall faces the masonry shows rusticated ashlar blocks, that is, dressed stones with pronounced raised faces which give the walls a textured appearance.

Approach to the site was concentrated at the north‑east. There the gate complex survives alongside a narrow neck ditch that is today water filled. This approach corridor and its defensive cutting remain visible in situ and mark the original principal entrance route.

The lower ward preserves two substantial horseshoe-shaped towers, one facing north and a second to the south. These curved artillery towers were constructed of masonry tied to the rock and dominate the lower courtyard in their present fragmentary state. Imagery and site descriptions also record a large lifting wheel, a crane mechanism, located in the area beneath or adjacent to the south tower; that device is attested in historic depictions and written descriptions of the site.

Higher on the western rock the north wall of the main hall, the palas, still stands alongside the remains of a watchtower. The watchtower carries oriel fragments that have been taken to indicate a garderobe function, showing that latrine facilities were integrated into the upper defensive range. The southern portion of the palas was destroyed by the rockfall of 1820, leaving the surviving masonry and tower fragments in place as partial ruins.

The 1820 collapse also revealed a rounded, inverted‑cone space cut into the rock. This cavern has been interpreted in different ways, most commonly as a deep cistern hewn to collect rainwater and occasionally as a dungeon. The cistern is cut directly into the sandstone and remains exposed where the slide removed overlying masonry.

An isolated eastern rock, accessible only by narrow passages carved into the stone, once supported a small tower and can still be reached on foot along those tight routes. The castle’s foundations rest in part on massive blocks of sandstone; one of these blocks, weighing on the order of 1,100 tons, became the focus of crack detection and stability monitoring in the early twenty‑first century. Sensors installed during that program were later replaced by manually readable monitoring devices to permit continued observation of the rock and masonry interfaces.

Overall the standing fabric appears as fragmentary wall lines, towers and rock-cut features fixed to the sandstone outcrops, with evidence of later conservation where masonry has been consolidated to protect the surviving elements.