ll withdrawn in itself, austere, heavy, full of shadows into which it disappears, soaked through by the polychromy of its windows and frescoes, the lower church speaks the mystic language of contemplation; it invites and introduces to the prayer, teaches to renounce the distractions of the century and to look for the true good: peace, spiritual joy, as humble Francis wished us.
The architectural style of the main aisle, of the cross vault and of the shallow apse, which make the original body of the church, has been balanced by the gothic of the chapels, added to it , together with the wings of the wide front transept, later on after 1270.
