The Basilica of the National Shrine of the Immaculate Conception is the largest Roman church in North America, the 10th largest in the whole world, and the tallest building in Washington, D.C. Opened and dedicated in 1959, this prominent Latin Rite Catholic basilica honors the Blessed Virgin Mary as Our Lady of the Immaculate Conception, the Patroness of the United States. The Basilica is located on Michigan Avenue in the northeast quadrant of Washington. An estimated one million pilgrims from around the country and world visit the basilica each year. The Basilica is sometimes confused with the Washington National Cathedral, also a National Historic Landmark, which is an Episcopal church chartered by Congress as the National House of Prayer.

The idea of a national shrine was first conceived in 1909 while constructions began in 1920 under Philadelphia contractor John McShain, on land donated by The Catholic University of America. The architecture of the Basilica is a mix of Romanesque and Byzantine styles. The interior is Greek-styled crowned with numerous domes decorated in mosaics, similar to the Basilica of St. Mark in Venice, Italy, but much larger. The mosaics feature American renditions of traditional Catholic images. Artist Jan Henryk De Rosen, who presided over the shrine's iconography committee, was also responsible for much of its decor, including composing the large mosaic over the northern apse. The spectacular ?Christ Pantocreator? mosaic on the inside dome alone makes it worth a visit. The Basilica proper (upper church) was completed after Vatican II while the lower or Crypt Church was completed prior to Vatican II. Hence, all of the inscriptions in the Crypt Church are in Latin, while those in the upper church are in English.

The Basilica doesn?t have its own parish community, but it serves its adjacent University, the United States Conference of Catholic Bishops, and hosts numerous masses for different church organizations across the country. The Basilica also features a gift shop where visitors can browse through a plethora of Catholic and Christian items such a medals, statuettes, icons, and books.