Brodnica Castle was built by the Teutonic Knights between roughly 1305 and 1339 as one of the order's regional strongholds, controlling the Drwęca river crossing. It saw heavy use during the Polish-Teutonic wars and changed hands several times before the order's collapse in 1525.
What survives today is dominated by the great brick keep — a square, octagonally tapered tower 54 metres high — together with fragments of the curtain wall and the chapel cellars. The tower can be climbed in summer for a fine view across the river and the surrounding lowlands, and the small museum at its base traces the history of the order, the castle and the town.