The Rookery is a possible medieval earthwork motte and bailey fortress. The eastern part of an elongated hillock may have been scarped into a motte, with the remaining platform becoming a bailey. Standing against the east bank of the River Cockmere, the earthwork is encased by wet ditches and with the dense cover of trees, the site is best viewed in winter. Nearby is Burlow Castle and a mile east is Wilmington Priory.