Arnsberger Schloßruine

The Arnsberg castle ruin crowns the 256-meter Schlossberg above the old town — the remains of a fortification established around 1100 by the Counts of Werl-Arnsberg. When the county passed to the Archbishops of Cologne in 1368, the castle became the administrative heart of the Duchy of Westphalia: prince-electors lodged here during visits, the Landdrost governed from within its walls, and regional diets were occasionally convened on the premises. A city fire in 1762 left the complex in ruins, and it is now a protected heritage monument. A well-marked trail climbs from Arnsberg's old town to the remaining walls, rewarding visitors with open views across the Ruhr valley and the forested ridges of the Sauerland.