McSweeney Doe Castle Co. Donegal is located on a rock at the inlet of Sheephaven Bay and is protected by sea on three sides, and by a moat cut into the rock on the landward side. It is an impressive fortified castle and has a central tower, battlements and a defensive wall enclosing a courtyard. The tower walls are about 8 feet thick and there is a dungeon on the third level . McSweeney Doe Castle was built in the 16th century and was a stronghold of Clan Suibhne (MacSweeney). Owen Roe O'Neill led the Irish Confederates from Doe Castle in 1642 in the Wars of the three kingdoms. During the 17th century, the castle changed hands a number of times, and was taken by the English hands. The castle is now a National Monument.