In a testamentary document of 1279 is for the first time mentioned the church of Santi Francesco e Lucia , which was then rebuilt in the first half of the XIV century, under the patronage of the Municipality that, although entrusting custody and officiation to the Friars Minor Conventuals, he considered it “Ecclesia Communis” and used it as a “second Town Hall”. The General Council and the Parliament met there. The voting box and a cabinet with the most important documents of the Municipality were kept there. Official religious celebrations were held, in which the administrators wore their dress.
...Originally, the church was built in a single hall and, in later times, it was enlarged on the right side and built four chapels. Inside the church there was a shop where the Municipality, in a monopoly regime, sold salt and, on the outside walls of the church, were hung the various measures available to the public. In the 19th century, the church and the convent suffered from the suppressions of the Regular Religious Orders. First during the Napoleonic Reign and then during the Unification of Italy. In 1881 the mayor Antonioli wanted to transform the church into a covered market. The citizens opposed stopping much of the project: the church was deprived of the initial part to leave room for a porch on the facade and on the left side, intended to accommodate the market. Inside the church are preserved the remains of the patron saint, San Gaudenzio, in a chapel dedicated to him and entirely frescoed with scenes of his life painted by Filippo Bellini from Urbino. Of remarkable value are the paintings of the side altars painted by Francesco Maratta, Marco Benefial, Federico Barocci and Ercole Ramazzani. Adjacent to the church, with main entrance on via Gramsci and a cozy cloister overlooking the square, is the palace of the Conventual Fathers. It was built in the 17th century as the seat of the Franciscan Conventual Fathers. Today it is home to the historical fund of the Library, the Historical Archive and the Museum “Città di Ostra”, which houses precious paintings (Francois Perrier, Andrea Sacchi, Claudio Ridolfi), precious wood sculptures and rare ancient volumes.