It is one of the most important Sienese churches.
For its size, its position on the hill of Camporegio from which it permanently “talks” to the Duomo, for its collection of artworks that has (just four examples: the Maestà by Guido da Siena, the fresco by Andrea Vanni depicting Santa Caterina, the only true portrait made during her life; the cycle of frescoes by Sodoma in the Cappella di Santa Caterina which contains the reliquary with the head of the Saint; the Adorazione dei Pastori by Francesco di Giorgio Martini), and for being the main place of the religious life of the Sienese saint.
The construction lasted over two centuries (from 1226 to 1465). The basilica has a severe and massive appearance with its bricks architecture, with its abnormal facade, smooth and without decorations. In the large fourteenth century crypt, with three naves, there is a large Crucifix painted by Sano di Pietro. Just below the Basilica, taking the Costa del Serpe, a road a bit hidden down below the hill, leads to Fontebranda fountain.
Very beautiful is the view of the back side of the church (transept and terminal chapels), that you can enjoy from the hill opposite to the one where the basilica stands, especially from Via di Diacceto.