Castell de Rocabruna, Medieval castle in Camprodon, Spain.

Castell de Rocabruna is a medieval fortress perched on rocky terrain at roughly 1000 meters elevation, built with thick stone walls and towers that follow the contours of the mountain. The structure features multiple sections adapted to the sloping ground, designed to command views over the surrounding valleys and mountain passes.

Documented in 1070 and again in 1087, the castle was held by the Llers family: Arnau de Llers swore homage to Count Bernat II of Besalú for the castrum de Rochabruna. It passed through the Cervià, Milany and Besora lines before Ramon Desbac acquired it in the 14th century. Pere Desbac, a supporter of Joan II, was named Captain General of the Mountain in 1471. After the Catalan Civil War the site lost importance and was abandoned in the 17th century, later used as a quarry.

The name Rocabruna comes from the dark, almost blackened colour of the soil and stones, including those in the walls. Local legends tell of a golden bull buried in the castle: after lightning struck a wall, neighbours came hoping the collapse had exposed it. Another tale recounts a siege during Arab times, when inhabitants dug a long tunnel down to the river for water.

Access is only by a half-abandoned path climbing from the foot of the hill past the houses of La Vila and Ca l'Arneta; the hill is entirely wooded and there are no marked trails to the castle. The GR-11 long-distance path (Molló–Beget section) runs below the hill, not to the ruins. Since 2006–2017 consolidation work, a delimited visitor circuit, viewpoints and explanatory panels have been installed on site.

A local legend holds that a golden bull is buried somewhere in the castle. The belief was so firm that after lightning struck and brought down an interior stretch of wall, neighbours came hoping the collapse had exposed the treasure. Another tale tells of a long tunnel dug down to the river for water during a siege.