The Cliffs are 8km long and 214m high, it is here that one can most easily get a feel for the wildness of the terrain over which the Celts wandered, for although they built imposing castles, very often they preferred the outdoor nomadic life and enjoyed the hunt. The tower was built in 1835 by Cornelius O'Brien, a descendant of Brian Boru. The High King of Ireland, and the O'Brien's of Bunratty Castle, Kings of Thomond, as an observation point for the hundreds of tourists who even then visited the Cliffs.

O'Brien's Tower is the best location from which to view the Cliffs, from this vantage point one can see the Aran Islands, Galway Bay, as well as The Twelve Pins and the Maum Turk Mountains to the north in Connemara and Loop Head to the South.