The Cliffs of Moher are located at the southwestern edge of the Burren region in County Clare, Ireland. They rise 120 metres above the Atlantic Ocean at Hag's Head, and, eight kilometres to the north, reach their maximum height of 214 metres just north of O'Brien's Tower, which is a round stone tower near the midpoint of the cliffs that was built in 1835 by Sir Cornelius O'Brien.