San Francesco is a 13th-century Gothic church on a small piazza in the centre of Cortona, founded by Brother Elias of Cortona, one of the closest companions of Saint Francis. The interior is plain stone with a single nave, but the small altar to the right of the entrance holds an ivory reliquary said to contain a piece of the True Cross, gifted by Brother Elias.
The fresco fragments along the side walls and the wooden crucifix above the high altar are worth a look. Compared with the better-known Cortona churches, San Francesco is quiet — often empty in the afternoon.