Beacon Hill is a mid 12th or early 13th century earthwork siege-castle, which has been severely damaged by the construction of a 20th century Royal Observer Corps post. The fortification which is crowned by a low rampart, was built during the Anarchy, in the reign of King Stephen or the minority of King Henry III. The oval hillock was scarped to create a steep-sided mound and encased by a ditch, with a counterscarp bank. There is a fine view of Pickering Castle, half a mile to the east.