Caerau Hillfort is a Scheduled Ancient Monument, comprising a 5.1ha. triangular, enclosed area measuring 400m (east-west) by 250m at the base. Its three earthwork ramparts with ditches are generally wooded, and the interior is pasture, formerly cultivated. There is a possible castle ringwork set at its north-east angle (NPRN 94518), with a church on its south (NPRN 301612). See also associated medieval settlement (NPRN15250). In 2011 the Department for Archaeology and Numismatics Amgueddfa Cymru – National Museum Wales along with Cadw and the Royal Commission funded a LiDAR survey of St. Fagans National History Museum and its environs including Ely. This work highlighted the distinctive triangular interior of the hillfort and the steep north and south slopes, both fortified by three massive ramparts with accompanying ditches. Further processing of the LiDAR data resulted in a ‘bare-earth’ digital terrain model, with houses and trees stripped away, revealing the magnificent sculpted ramparts and ditches.