Behind the main altar, there is a polyptych with five compartments dating back to 1348, probably by Ugolino Lorenzetti, The Master of the Ovile Madonna (however some art historians lean towards Bartolomeo Bulgarini). It depicts the Madonna and Child seated on a throne surrounded by Saint Michael the Archangel, Saint Bartholomew the Martyr and John the Baptist, and was reproduced to give the idea ofthe original composition of the work.
