Burg Langensteinbach, Castle ruin in Langensteinbach, Karlsbad, Germany

Burg Langensteinbach, also called Römerturm, is the ruin of a hilltop castle on a hill south of Langensteinbach, a district of Karlsbad in Baden-Württemberg. Only the restored stump of the residential tower and a surrounding ditch-and-rampart structure remain. The tower's foundation walls were 3.5 metres thick, and the tower was probably originally 35 metres high. The ruin of the later St. Barbara Chapel stands immediately next to it.

The castle was built around 1100 and served as a residence for local nobility before being abandoned around 1200. After that, the structure gradually fell into decline, leaving only portions of the residential tower standing today.

The ruin is also called Römerturm, though it has no Roman origin. Beside it stand the remains of the later St. Barbara Chapel, a ruined chapel rather than an active parish church. The tower stump was restored after excavations in the 1970s.

The ruins can be reached on foot via walking paths from Langensteinbach and sit on a hillside offering views of the surroundings. The paths are walkable without special equipment, but sturdy footwear and a steady pace are recommended for the climb.

The castle is also called Römerturm, though it has no Roman origin: the name arose later. The tower's base walls were 3.5 metres thick and it may once have stood 35 metres high. After a fire, a moat was dug right against the foundations to protect against siege engines.