Green Hill is probably a small medieval earthwork motte and baileys fortress, built on a narrow ridge. Sited south-east of the rampart enclosing the outer bailey of Wigmore Castle, are two inconclusive earthworks mounds. The circular eastern mound is the motte and separated by a broad ditch, is a narrow rectangular western bailey platform. Houses have encroached upon the eastern bailey, of what could be a temporary outwork or a siege-work of 1155.