The ambulatory with eleven chapels

Eleven chapels surround the basilica's interior, forming an extensive arrangement of rooms with the ambulatory. The covered passages have an outer outline resembling a square about 50 metres across. The nave itself is not square: both the nave and chancel have oval plans, with their axes set at right angles to each other.

Chapels were added to the ambulatory during the church's eighteenth-century reconstruction. Rather than a single straight corridor, this produced a sequence of differently shaped spaces. Angled structural elements reduce the number of square corners, while passages connect this part of the building with the central church interior.

The chapel scenes begin the Calvary's biblical narrative. They cover the life of Jesus from his birth to his baptism in the Jordan, and Mary's story from the Annunciation to the Assumption. Further scenes continue outside the church, in chapels throughout the village and on its hills. The ambulatory is therefore the beginning of a larger sequence connecting the basilica with the pilgrimage complex.