The 'Confession' - Tomb of Saint Peter (La tombe de Saint-Pierre; Petrus grab).by Carlo Maderno;1615-17The Confession (crypt) opens under the center of the dome. This underground church at the height of the Constantinian church preserves the tomb of St. Peter; and is really the 'heart of the Basilica'. The word 'Confessio' refers to the Confession of faith by St. Peter which lead to his martyrdom. St. Peter's tomb is behind the Niche of the Pallium. Vatican 2019Photo: Eric Vandeville