The ambulatory is a circular corridor which allows pilgrims who follow it to venerate the relics. This place in St. Sernin is rich with reliquary
cupboards of the 17th century, whose décor illustrates the lives of the saints.
The axial chapel in the middle of the apse has facing it a bas-relief in marble of Christ in Majesty. It is by Bernard Gilduin, and was made at about the same time as the romanesque altar. On either side of this statue are fine sculptures of angels, mounted on the curving wall. The ex-voto hanging nearby represents in wood the city of Toulouse. It was offered by the Capitouls of the city in 1528, to thank St Sernin for his intercession and his protection during an epidemic of the plague.
The presentation of the relics of the saints in the ambulatory invites pilgrims and the faithful into the cortège of the heavenly Church which the order and the harmony of the whole building suggest. The liturgical processions past the Holy Bodies are an image of the road of the terrestrial Church towards Heaven, with the support of the intercession of the saints who are already in glory. These processions take place at Pentecost, on the festival of All Saints, and on November 29th, the feast of Saint Saturninus.