The gatehouse in the centre of the south curtain wall mostly dates from the 13th century. It was originally accessed via a drawbridge and visitors had to pass through two gates, one at either end of the passage, and a portcullis. The semi-octagonal projections on either side of the gate passage are considered ornamental. Between the projections and above the gate were machicolations, openings for missiles to be hurled at attackers. The rooms on either side of the passage were guardrooms. The only remaining openings on the front are slits at ground level. Slits on the other sides of the gatehouse, and along the entrance passage, allowed the gatekeeper to watch people approaching and entering the castle. The structure underwent later alterations in the 19th and 20th centuries when it housed the castle's custodian; slits in the gatehouse's front may have been filled in.
