O'Rourke's Tower: Though named O'Rourkes' Tower, after 10th-century Connacht king Fergal O'Rourke, the "Chronicum Scotorum" records that it was finished in 1124 by Turlough O'Connor, king of Connacht, and Gilla Christ Ua Maoileoin, abbot of Clonmacnoise. 11 years later it was struck by lightning which knocked off the head of the tower. The upper part of the tower is later work, so there is some speculation that the masonry thus toppled in the storm of 1135 may have been reused in the building of McCarthy's Tower.