Breitenstein Castle, Rock castle in Elmstein Valley, Germany

Breitenstein Castle is a ruined rock castle on a narrow crag 220 metres above the Speyerbach valley. Its shield wall of rusticated ashlars survives almost to full height, with a sloping right edge seen from the hill side and Gothic corbels on the inner walkway. Behind it are the partial walls of a modest dwelling, reached by a rock-cut staircase on the south side.

Construction began in 1246 under Pope Innocent IV as a response to conflicts with Emperor Frederick II. The fortress played a role in medieval power struggles between papal and imperial interests in the region.

The name Breitenstein first appears in 1257 with a knight of Kropsberg, castellan of the Breitenstein; by 1265 the knight called himself Burkhard of Breitenstein. The 1357 Burgfrieden treaty renamed the parts: the larger siege castle became the main castle and the older complex the outer ward. Visitors can still see the corbels of the wall-walk, which already show Gothic forms.

The ruins sit above the hamlet of Breitenstein, part of Esthal, on a slope above the Speyerbach valley; the L499 runs along the valley floor and branches off the B39 at Frankeneck. The core castle stands on a narrow rock base reachable today only by experienced climbers, so the shield wall and neck ditch are best viewed from below.

Rather than a traditional moat, access was engineered through stairs carved into the rock itself. This unusual design shows how builders used the natural geology to create defensive advantages.