The Romano-Byzantine Sacre Coeur Basilica overlooks Montmartre, one of Paris's most picturesque districts. Its distinctive travertine stone dome rises up over the rooftops, allowing visitors to the basilica the perfect vantage point from which to survey the city. Within Basilica of the Sacred Heart of Jesus, often called Sacré-Cœur, visitors will find several interesting sites, including a mosaic of Christ, an elegant organ constructed by Aristide Cavaillé-Coll, and a crypt. Commissioned by the Catholic Church, construction began in 1875 under the watchful eye of architect Paul Abadie, and was finally completed in 1914.