Built during the 14th and 15th centuries on the site where a Roman temple used to stand, its neoclassical facade (which was the crowning work of Ventura Rodríguez) hides a magnificient Gothic Church whose central nave reaches a height of 28 metres.

The building work is very simple and light enters through pointed windows with some 16th century stained glass and other later windows. The figure of Saint Mary that presides over the cathedral is a Romanesque silver-plated sculpture. In the central nave stands the tomb of King Carlos III and his wife, Leonor, a superb example of 15th century Gothic sculpture.

The altarpiece is the jewel of the Cathedral and one of the best examples of the Gothic style, with trefoiled arches, mullions, vaults, and doors decorated with highly varied and exquisitely detailed sculptures.

The Cathedral buildings are completed by the canons' kitchens, in Rococo style, and the English Gothic refectory, which houses the Diocesan Museum and its valuable collection of sacred art.