Conisbrough Castle was the principal northern stronghold of the de Warenne Earls of Surrey from 1069 until 1347. In 1180, the fifth Earl, Hamelin Plantagenet ordered the construction of the stone Keep. The circular Keep, is supported by six solid buttresses and stands to a height of 27 meters. In 1994, following five centuries of neglect, two new floors and a roof were placed into the Keep, protecting it from the elements for generations to come.