Also known as Peveil or Castleton Castle. The ruins of a medieval keep castle predominantly dating from the 11th to the 14th century. Among the first of the Norman castles to be built in England after the Conquest and granted to William Peveril, who was thought to have been an illegitimate son of William I and one of his most trusted knights. The castle stands in an impregnable position on a clifftop above the town of Castleton but precedes the town by about 100 years. In 1080 Peveril fortified the site and constructed a wooden keep but later these buildings were converted into stone. The square keep and part of the curtain wall are still standing and the outer bailey is still visible. Part of the north wall dates from the 11th century but the remainder is 12th to 14th century. The castle fell into disuse during the 15th century and was never adapted for domestic use. Only the keep was in use by the 17th century as a courthouse. When this was abandoned the castle gradually became ruined until restoration work during the 20th century. The present stone keep, built by Henry I in 1176, survives almost to its full height. Inside the courtyard it is possible to trace the foundations of a Great Hall, kitchens and other domestic buildings.