This magnificent cathedral took almost 3 centuries to build, from 1254 to 1517. The original Romanesque structure was replaced bit by bit; first the choir, then the tower, and finally the nave and transepts. The nave collapsed during a violent storm in 1674 and was never reconstructed; the choir and transepts survived and remain disconnected from the tower . The cathedral interior bears traces of the fierce wave of iconoclasm that spread over Holland in the second half of the 16th century. There's a battered altarpiece in one of the side chapels. A sandstone Holy Sepulcher, dated 1501, shows a defaced Christ in a tomb under a badly damaged Gothic arch.

Other worthwhile sights nearby are Bisschopes Hof, or Bishop's Garden (daily 11am-5pm); and Dom Kloostergang, a cloister arcade constructed in the 15th century, with magnificent stained-glass windows depicting scenes from the legend of St. Martin. The cathedral cloisters are connected to the former Hall of the Chapter, where the signing of the 1579 Union of Utrecht (which united the seven Protestant Dutch provinces in their rebellion against Catholic Spanish rule) took place.