Castle Coch is chiefly known as a romantic folly supposedly reproducing a small medieval Welsh chieftain's stronghold, built in the 1870s, for the 3rd Marquess of Bute to a design by William Burges, and possessing the most remarkable interior decoration. However, it was built upon the remains of a genuine 13th century castle built in two stages. Evidence was found of the building having been deliberately slighted by mining.