 The upper image shows the area of the lower floor of St. Peter's Basilica that lies above the site of Saint Peter's tomb.A portion of the aedicula that was part of Peter's tomb rose above level of this floor and was made into the Niche of the Pallium which can be seen in the center of the image.The earliest reference to Saint Peter's death is in a letter of Clement, bishop of Rome, to the Corinthians ("1 Clement", a.k.a.