Built as the market neighborhood's answer to Notre-Dame, this massive church is decidedly squeezed into its surroundings. Constructed between 1532 and 1640 with foundations dating to 1200, the church mixes a Gothic exterior, complete with impressive flying buttresses, and a Renaissance interior. On the east end (Rue Montmartre), Dutch master Rubens' Pilgrims of Emmaus (1611) hangs in a small chapel. Two chapels to the left is Keith Haring's The Life of Christ,
a triptych in bronze and white-gold patina: it was given to the church after the artist's death in 1990, in recognition of the parish's efforts to help victims of AIDS. On the Rue Montmartre side of the church, look for the small door to Saint Agnes's crypt, topped with a stone plaque noting the date, 1213, below a curled fish, an indication the patron made his fortune in fish.