Mondolfo is on a pleasant hill and overlooks the Adriatic Sea. It's in the southern part of the province of Pesaro and Urbino, near the Cesano estuary. In an area already inhabited since the Eneolithic age, a Byzantine castle in the VI century was built at the top of the hill and around the XI century took place the encastellation of the small town. In order to escape the dangers of the valley, because of the arrival of Barbarians, the population, in particular from the resort of St. Gervasio, found shelter on the hills of Mondolfo (the resort of St. Gervasio is situated in the southern area of Mondolfo) where there was an important monastery, of which only the superb church is left.

The abbey of St. Gervasio (5^th- 6^th century) is right at the centre of an archeological area.  Most probably it was built on a site already known by the Romans. In  the crypt there’s biggest sarcophagus of the Marche  and it dates back to the 6^th century b. C. It preserves corpse of St Gervasio, the ancient patron saint of Mondolfo whose cult was started in 386 by St. Ambrose.  Starting from this abbey the Cesano valley was converted to Christianity.

The monastery is of basilical shape. Its origins go back to the pre- Christian age. Then it turned into a Romanesque church with a nave and two aisles and finally in 18th century style.