Basilica of the National Shrine of the Immaculate Conception
Since its dedication in 1959, this Byzantine-Romanesque shrine to the Virgin Mary has welcomed over one million visitors a year, among them Pope John Paul II, Pope Benedict XVI, and Mother Teresa. At more than 77,500 square feet, it is the largest Catholic church in the Western Hemisphere and the eighth-largest church in the world. Walking through the basilica, 70 ornate chapels, oratories, and sacred images like the Our Lady of Guadalupe Chapel flank the sides of the upper church and crypt, and the shrine's gorgeous ceiling bears one of the largest and most intricate mosaic renderings of Jesus. Named “Christ in Majesty” (some have humorously nicknamed it “The Scary Christ” due to his stern look), it's made up of over three million tiles.