Of great artistic interest is the Romanesque-Gothic parish church. It was built in the 11th century, although its first roots date even further back.
As San Polo is situated on the border between Siena and Florence, the church and the adjoining rectory, the courtyard with its cistern and even the church tower were converted into a fortified castle in the 13th century.
The large church is laid out as a three nave Romanesque basilica, and was renovated after a fire in gothic style in the 14th century. The vaulted ceilings of the main nave are decorated with outstanding frescos in the style of Ambrogio Lorenzetti. They date back to the year 1367 and portray the life of Christ.
The small, but fully functional organ from the late 18th century provides beautiful musical accompaniment.
The Chapel only opens at religious functions.