Koretsky ruins of the castle with a distinct red brick Gate Tower is the hallmark of the city. The first wooden fortification built in the XV century. was over. Korchik Prince Ostrog. Later the castle passed into the possession of Volyn governor Boris Koretsky, which strengthened its stone walls with towers and bastions, earthworks and circled by a moat, filled with water from a river. In the XVIII century. fortress building served as the basis for building a palace princes Chartoriyskis. In 1832 the palace was burnt and has since not recovered. Gate preserved three-storey tower adjacent to it ruins the exterior walls of palaces and cities trehpilonnyy chetyreharochnyy (reconstructed in recent years).