The origins of Serra San Quirico date back to ancient times because of the key position of the place. A number of historical documents are found in the area that speak of ancient times, with tangible signs of Etruscan, Picene and Roman civilization; as well as the discovery of a necropolis of Galli Senoni. The Romans, in order to control the strategic passage from the Gola della Rossa, founded a military garrison around which the original village developed. Destroyed by barbarian invasions, in the early 1000s St. Romuald contributed to the rebirth of the village by having a church built.
Thanks to the intervention of the Papal State in the 12th century, Serra San Quirico became a citadel with its fortifications for the protection of the surrounding area.
The beautifully preserved historic center features the characteristic 14th-century medieval layout. The Copertelle, the true symbol of the village, are covered passageways that run along the village walls.
On the slopes of the Monti del Sole, rises Domo, the first of the four castles of Serra San Quirico, surrounded by walls that reveal its character as an ancient fortification, which is presumed to have been founded by some Osimani who fled their city besieged by the barbarians.