St Mary-in-Castro church was built around AD 1000, before the Norman Conquest. The pharos is a Roman lighthouse and the oldest building in the castle. The Duke of Suffolk’s Lodgings is a castle building modified for the Duke of Buckingham in 1625-1626 and again as a barrack in 1744-56. Colton’s Tower was the entrance to the middle bailey. The curtain wall of the middle bailey was built in the early 13th century and continues around the church.