Burg Hollenburg, Medieval castle in Köttmannsdorf, Austria.

Burg Hollenburg sits on a steep rock hill above the Drau River and combines different architectural styles from Renaissance to Gothic. The castle complex has an open courtyard, an eastern chapel, and terraces that look out over the river valley.

The castle was founded in the 12th century and the Hollenburg family managed it from its first mention in 1142. An earthquake in 1348 damaged the buildings severely, which led to major reconstruction work.

The chapel displays Gothic frescoes and the courtyard holds Roman stone reliefs that show the connections between medieval and ancient times in this region. These artworks tell the story of different cultures that have shaped this place.

Burg Hollenburg is privately owned and not open to visitors; the grounds and buildings can only be viewed from outside. The castle stands at 561 metres on the northern slope of the Drava valley near Köttmannsdorf, and the access road on the north side crosses a neck ditch. Visitors reach the area on foot or by car from Köttmannsdorf.

The castle courtyard holds reliefs and inscriptions from Roman-era grave buildings, built into the walls centuries after they were carved. The chapel of St Nicholas, in the ground floor of the east wing, keeps a fresco cycle from the second half of the 14th century.