In the medieval period Roquemaure was the site of an important castle that stood on a limestone outcrop in the Rhône. The surviving ruins include two towers, the Square Tower ("Tour carrée") and the Round Tower ("Tour ronde") that date from the 12th and 13th centuries. Next to the Round Tower are the remains of a toll collector's house that dates from the same period. The ruins are currently privately owned. On the opposite bank of the Rhône is a similar limestone outcrop on which sits the ruins of another medieval castle, the Château de l'Hers. In the medieval period the Rhône was somewhat wider at this point than it is today and both castles sat on islands within the river.