The first document of the sanctuary dates back to 778 when the Duke of Spoleto, the Lombard Hildebrand, gave the church and the territory of San Donato to the Monastery of San Vincenzo al Volturno. There are traces of the initial small church. The current building is 26 meters long and has three naves with a dome 18 meters high. Inside there are frescoes by Gaspare Capricci representing the most significant moments of the holy life. The bell tower was originally a thirteenth-century watch tower.