Acklam Castle is an earthwork motte and bailey fortress, which was possibly an outlying stronghold of the Fossard family. Standing on the western edge of an east-west ridge, the castle was formed by the digging of two simple transverse ditches. In the top of the low motte is a shallow depression and stone structures have been identified in the large rectangular bailey. From the road farm buildings make the layout hard to observe. A mile west is Leppington and 4 miles north at Langton is an earthwork.