Today the ex-church houses the city museum (Museo Comunale); it stands within the city walls in a place known as Castelvecchio (old castle) that was once the residence of the Olivi and Fortebracci families. Built in the 1300s, the church has the simple design of the orders of poor friars, with a single aisle, a roof truss and a polygonal apse. The real value of the ex-church is due to the exquisite frescoes still preserved there. They were painted in the 1400s by various artists that worked in the town on commission of the ruling Fortebracci family.
Of the frescoes, particularly significant are the following: those with scenes from the life of St Frances (scene di Vita di S. Francesco); the one showing the Last Judgement (Giudizio Universale), painted by Antonio Alberti between 1423 and 1424; and the one depicting St Anthony of Padua (S. Antonio da Padova) standing between John the Baptist (Giovanni Battista) and the archangel Gabriel (Archangelo Gabriele), painted by Bartolomeo Caporali in 1491.
According to historical sources, beginning in 1308 and later during works to expand the building in the 1500s, the convent was annexed to the church (now also part of the city museum).
In the 1700s a fire as well as an invasion by Napoleon caused extensive damage to the complex; it was salvaged and restructured in the 19th century when it became property of the state under control of the newly-formed Italian State.