The cathedral is considered a fine example of a balance between Romanesque and Gothic architecture. Its unusually wide Romanesque nave, with no side aisles, opens into a Gothic transept and choir.
The mid-12th-century portal was inspired by the Portail Royal in Chartres and centers on a depiction of the Apocalypse. The portal's statues depict figures ranging from the Queen of Sheba to David with his harp.
Inside are the stained-glass windows (12th-16th centuries) for which the cathedral is famous. The oldest one illustrates the martyrdom of St. Vincent; the most unusual is of St. Christopher with the head of a dog.
The most beautiful is a 13th-century painted glass window in the transept depicting the life of Saint Julien. Also in the transepts are two 15th-century rose windows, with earthly suffering in the north facing Christ in Glory in the south.
Other notable works of art include remarkable decorative paintings from the 13th century (just discovered in the early 1980s) and a few of the famous Apocalypse Tapestries. At one time they all hung here, but the majority are now on display in the nearby Angers château.