The castle is now entered through the 13th-century southern gatehouse, which faces towards the former deer park. This entrance was once protected by a 14th-century fortified bridge, also called a barbican, but only one set of stone arches remain, showing two surviving arrow slits in arched recesses. The south gatehouse has two drum towers on either side of a gateway, protected by a portcullis, and would have had three floors, linked to a wall walk around the castle. It would originally have been faced with dressed stonework, which has since been removed. The north gatehouse on the opposite site of the bailey originally led into the town of Launceston. The first floor of the building was probably first used as the porter's room, then by the castle's constable, and finally later as a prison.