The Basilica of the National Shrine of the Immaculate Conception is located in Washington, D.C. It is one of the largest churches in the United States and serves as a prominent place of worship for Catholics. The basilica is dedicated to the Virgin Mary under her title of the Immaculate Conception, which celebrates her conception without original sin. Construction of the basilica began in 1920 and was completed in 2017, featuring a blend of Romanesque and Byzantine architectural styles. It houses numerous chapels, mosaics, and artworks that reflect the rich traditions of the Catholic Church. The basilica is also a national sanctuary and a popular pilgrimage site.