Basilica of the National Shrine of the Immaculate Conception

Dedicated to the Virgin Mary, the largest Roman Catholic basilica in North America and one of 10 largest churches in the world blending Byzantine and Romanesque architecture. Largest collection of contemporary ecclesiastical art in the world. Undercroft of more than 70 chapels and oratories. Tours: free audio or guided M-Sa. Cafeteria, gift store, book shop. Open daily. Free.