Built during the 11th century and solemnly consecrated in 1077 in the presence of William, Duke of Normandy and King of England, the Romanesque cathedral is one of the finest examples of Norman Romanesque art. Its Gothic features were added as from the late 12th century, transforming the greater part of the edifice. The last addition during the Gothic period was the central tower, erected in the late 15th century and crowned with a copper dome in the 19th century. No visits during church service. Guided tours of the treasure room and the chapter house every day throughout July and August at 3 p.m. (entrance fee).