The south-west corner tower of Gleaston Castle, seen behind the farm house, is understood to have been the initial module of what became a four tower castle with high linking walls forming a rectangular enclosure.  John de Harrington I, Lord of Aldingham and Muchland began the construction around 1297.  For the last five hundred years or so the castle has been allowed to  slowly deteriorate until today it is judged to be beyond conservation and to be unsafe to enter.