Caerau Hillfort - Bryngaer Caerau Hillfort is a large Iron Age site and covers an area of 13 acres. It was constructed on the site of a previous Neolithic site. There is evidence of Norman ringwork castle on part of the site. This triangular hillfort would have had a bank and ditch for outer protection. It is located on the A4232 at Caerau, southwest of Cardiff.