Oxford Castle is a Norman motte-and-bailey castle built shortly after the Conquest of 1066. The main surviving medieval features are the mound (motte), the 11th-century St George's Tower, and a crypt beneath the former chapel. In Victorian times the castle was expanded and converted into a prison, which operated until 1996. The prison complex is now a hotel, restaurant, and visitor attraction — a decision that caused some controversy but has preserved the buildings well.
Guided tours of the castle run regularly and include the atmospheric medieval crypt and St George's Tower, from which there are good views across the western side of the city. The old prison wings are incorporated into the Malmaison hotel. The site is also home to the Oxford Castle Quarter, an open-air area with restaurants and bars that is particularly lively in summer. The castle is set slightly apart from the main tourist circuit, about five minutes' walk west of Carfax, and can be combined with a visit to the covered market.