Erddig Castle is a late 11th century earthwork motte and bailey fortress, which was probably founded by Hugh de Avranches, earl of Chester. A bluff above the confluence of the River Clywedog and the Black Brook, was cut through by scarps and deep ditches, to form an oval motte and a subrectangular bailey. Also on the western side of the site, runs Wat's Dyke an 8th century defensive boundary earthwork. There are two entrances to the bailey, one opposite the motte and the other at the south-west corner and the rounded projections on the angles and along its southern side may have been associated with timber towers. 'The castle of Wristleham' was mentioned in King Henry II pipe roll of 1161 and in 1574 the site was called the 'ruin of a castell great'. Sadly the site has been altered by mid to late 18th century landscaped gardening, associated with Erddig Park. 6 miles north is Caergwrle Castle and 10 miles south-west is Castell Dinas Bran.