Burg Schlosseck, Medieval castle in Bad Dürkheim, Germany.

Burg Schlosseck is a medieval castle on a ridge near Bad Durkheim, situated at about 300 meters in elevation. The position offers wide views across the Isenach valley and surrounding landscape.

The oldest masonry dates to the 9th or 10th century, when an early medieval refuge fort was built against Norman raids. In the early 13th century the Counts of Leiningen, judging by the territorial situation, had a new castle built on the site; archaeology shows it burned within the same century yet was still inhabited in the 14th. Christian Mehlis dug here in 1879, and the portal was rebuilt from finds in 1883–84.

The castle displays eagle reliefs on its portal that reflect the decorative craftsmanship of medieval German fortifications. These carved details show the skilled stonework that once characterized such defensive structures.

The ruin stands on a spur of the Rahnfels at 303 m above sea level above the Isenach valley near Hardenburg. The castle portal was rebuilt from finds between 1883 and 1884, so look for the eagle reliefs and the keystone with a leaf mask in the arch. The site has belonged to the state palace administration of Rhineland-Palatinate since 1963, and conservation work was carried out in 1988 and 1989.

The low height of the surviving walls and the absence of rubble and of any palas suggest the castle was never finished and was only lived in temporarily, in a provisional state. Its five-sided bergfried, 8.5 by 11.5 metres with 2.5-metre walls, sits in a three-metre-thick shield wall.