The moment you enter, the scale stands out. A long central nave stretches ahead, lined with tall marble columns. Above, the famous gilded coffered ceiling gleams traditionally said to be decorated with gold brought from the New World. Light filters in softly, giving the whole space a warm, sacred glow. Ancient Mosaics (5th Century Masterpieces): Looking along the upper walls, travelers will see some of the oldest Christian mosaics in Rome, dating back to the 400s. Scenes from the Old Testament Rich colors and storytelling imagery These mosaics are a major highlight because they’ve survived almost unchanged since the early Church. The High Altar and Holy Crib Relic: Beneath the main altar lies something very special: The Crypt of the Nativity Said to contain relics from the manger of Jesus (the “Holy Crib”) This is why the basilica is sometimes called the “Bethlehem of Rome.”