 The castle sits on a small peninsula, surrounded on three sides by water, with a moat cut into the rock of the landward side.The structure consists mainly of high outer walls around an interior bawn with a four-storey tower-house/keep.Doe Castle was most likely built in the 15th century by the O'Donnell family, but by the 1440s it had come into the hands of the gallowglass MacSweeney family.