Basilica of the National Shrine of the Immaculate Conception - among the world's largest Catholic churches

The Basilica of the National Shrine of the Immaculate Conception in Washington, D.C., is the largest Catholic church in North America and is widely cited as one of the largest Catholic churches in the world. Construction began in 1920 and the complex features Romanesque-Byzantine architecture, extensive mosaics, and seating for thousands of worshippers. The basilica functions as a national shrine and regularly hosts major liturgical events and pilgrimages.