Liebenstein Castle, Medieval castle in Kamp-Bornhofen, Germany.

Liebenstein is a stone castle overlooking the Rhine valley with fortified walls and towers that display medieval military engineering. The structure consists of several connected buildings built across the steep hillside terrain.

Built in the 13th century as an outwork of Sterrenberg Castle, Liebenstein was enlarged between 1284 and 1290 by Albrecht von Löwenstein against his uncle Werner VI von Bolanden. In 1294 and 1295 Heinrich I von Sponheim-Bolanden mortgaged both halves to the Schenk and Ludwig von Sterrenberg, who took the name von Liebenstein. A gate tower followed in 1363 and a defensive tower around 1380; by 1529 the castle was uninhabitable.

The name Liebenstein was adopted by the Sterrenberg castle-men Siegfried Schenk and Ludwig von Sterrenberg after the halves of the castle were pledged to them in 1294 and 1295. The legend of the "feindlichen Brüder" (hostile brothers) grew from the second shield wall built at Sterrenberg by Kurtrier in the 14th century, probably facing Liebenstein; Heinrich Heine made it the subject of his poem "Zwei Brüder" in the Buch der Lieder. No armed clash between the two castles is documented.

The castle is entered from the south along a narrow, steep access road with only a few parking spaces in front of the entrance. The Rheinsteig long-distance trail on the right bank of the Rhine passes over the castle. The main residential tower and its annex now house a restaurant with a castle garden and viewing terrace, and a hotel with rooms facing the Rhine.

Liebenstein and Sterrenberg stand only 200 metres apart on the same right bank of the Rhine, not on opposite sides. Kurtrier built Sterrenberg's second shield wall, the "Streitmauer", probably facing Liebenstein; this is the historical core of the "feindlichen Brüder" legend, though no armed clash ever occurred. Heinrich Heine retold it in his poem "Zwei Brüder" in the Buch der Lieder.