After the first Cella Memoriae built by the emperor Constantine the Great, and the second "Basilica of the 3 Emperors" consecrated by Pope Siricius in 390, this is the third edifice built to honor the memory of the apostle Paul. The main altar of the church is placed exactly where the tomb of Paul was found at the beginning of the 4th century, and today the same altar is crowned by a late 1200 ciborium of a rare elegance (by Arnolfo di Cambio). Interesting is the structure of the interior: about 440 ft. long with its 5 nave divided by 80 columns it still reflects the size and proportions of the early Christians basilicas of the constantinian time. Very beautiful is also the four-sided portico preceding the edifice: you may admire there the 150 granite columns, the garden, the mosaic decoration of the faÇade made by Filippo Agricola.