This imposing Flamboyant Gothic church lies at the heart of St-Michel. Begun in the 14th century, it took more than 200 years to complete and is best known for its impressive stained glass. With the exception of those in the Chapelle de Mons, all the original windows were destroyed during WWII, but the 1960s stained-glass windows are truly dazzling. Like the cathedral, the 114m-tall bell tower – nicknamed La Flèche – stands apart from the church and can be climbed. Views are panoramic.