Newcastle Castle

Newcastle Castle is a Grade II* listed building with a polygonal plan. It features a curtain wall that includes west and south towers, with a natural cliff providing defense to the east. The structure is made of Sutton stone and has coursed rubble facing stones, some of which have been removed or lost, particularly on the eastern side. The southern side retains substantial amounts of masonry, including a rectangular tower that has 2-light windows with voussoir relieving arches. This tower is flanked by a fine raised gateway dating from around 1175 to 1180, which is the most complete of its kind in Glamorgan. The gateway features a blind tympanum situated between semicircular and segmental arches, with the latter being billet moulded, as are the jambs beside Romanesque shafts that support roll moulding.

Additionally, there are remains of the keep to the west and the footings of the hall range to the east. The site is designated as a Scheduled Ancient Monument GM063.