Τhe traditional seat of the kings of Munster for several hundred years prior to the Norman invasion. In 1101, the King of Munster, Muirchertach Ua Briain, donated his fortress on the Rock to the Church. Few remnants of the early structures survive, the majority of buildings on the current site date from the 12th and 13th centuries.
The oldest and tallest of the buildings is the well preserved round tower 28 meters, dating from c.1100. The chapel of King Cormac Mac Carthaigh, was begun in 1127 and consecrated in 1134. It is a sophisticated structure, with vaulted ceilings and wide arches. The Chapel was constructed primarily of sandstone which has become waterlogged over the centuries, significantly damaging the interior frescoes. The Cathedral, built between 1235 and 1270 and the Hall of the Vicars Choral was built in the 15th century.
The complex has a character of its own, unique and native, and is one of the most remarkable collections of Celtic art and medieval architecture to be found anywhere in Europe.