This abbey was started in 1326 and completed in 1475. It is 86 m long, 12m wide in the nave and 55 in the transept.

Outside : it is made of brick and has a sober imposing aspect. The ridged facade is enlivened with marble sculptures.

The portal is gabled and decorated with statues and high reliefs in the lunette; several coats-of-arms in the brickwork of the facade and a very fine large rose window with the symbols of the Evangelists within a large frame is beneath the crowning gable. On the aisles are seven very high narrow double windows crowned with pointed arches.

Inside : The church has the shape of an Egyptian cross with a transept, a square apse, bare beams beneath the roof and a very huge single nave.

A wonderful atmosphere of meditation and ecstasy empathized by colored light pouring in through the beautiful stained glass windows fills the place.

Works of art :
Visitation and Saints ; fresco by Martino di Bartolomeo
Statue of St. Francis of the school of G.Pisano.
Madonna and Holy Child, a panel painted by Andrea Vanni.
The Crucifixion, a detached fresco by Pietro Lorenzetti.
St. Ludovico d'Angio' a detached fresco by Ambrogio Lorenzetti
Madonna and Holy Child; a fresco by Ambrogio Lorenzetti's school.
Other fine works of art by minor artists.