Burg Beyenburg, Medieval castle ruin in Wuppertal, Germany

Burg Beyenburg is a vanished spur castle on a rise in a bend of the Wupper next to Steinhaus Monastery in Wuppertal-Beyenburg. Only the levelled, unbuilt castle area and two retaining walls on the slope remain; the site is privately owned and protected as a Bodendenkmal since 22 November 2004.

The fortress was first documented in 1336 and held strategic importance between the counties of Berg and Mark. It controlled major trade routes from Cologne northward until destruction ended its role in regional conflicts.

The name Beyenburg also denotes the surrounding district of Wuppertal, and the former castle site lies beside the Steinhaus monastery on a meander of the Wupper. The castle administered the Bergish office of Beyenburg, and the flat, unbuilt castle area with two retaining walls is now a protected Bodendenkmal, recognized on 22 November 2004.

The former castle grounds are private property and not open to visitors; the site can only be viewed from the surrounding paths. The two surviving retaining walls on the slope and the undeveloped plateau above the Wupper are protected as a Bodendenkmal, so walking on the terrain is not permitted.

The castle stood on a neck of land inside a meander of the Wupper, guarding the farming and fishing settlement within the loop and a border bridge over the river about a kilometre away, on the boundary between the counties of Berg and Mark.