Serra Sant'Abbondio is situated on the left bank of the Upper Cesano Valley, below the eastern slopes of Mount Catria (1702 m). It still retains the layout of a medievalf fortified town, with two original  gates, the Porta Santa (with clock tower above it) and the Porta Macione (13th Century). Must see attractions are the church of San Biagio with the fifth century crypt  and Fonte Avellana Monastery, which is located on the slopes of Mount Catria. Founded in 980, visited by Dante in 1310, and once presided over by St Peter Damian, is one of the few monasteries in the Marche which retains its medieval monastic form. It boasts an extraordinary scriptorium and was once an important centre for the production of illuminated manuscripts and was built with an ingenious system to maximise the hall's natural lighting. There is also the Dante Alighieri Library, with rows of rare Seicento books and, of course, the church, with a simple single aisle and a flight of wide steps up to a raised presbytery. Beneath it, there's the crypt, supported by fine Romanesque arches, which is built with such finely cut stone that it seems almost as if the walls have been carved straight out of the rock. The most important event taking place in Serra Sant'Abbondio is the Palio della Rocca, a spectacular joust ending with a geese race.