At the foot of the Nerone Mount, in the hamlet Massa near Cagli, there was the abbey of St. Peter from Massa. Nowadays only the church is left. It was founded in the ninth century although it was first documented in 1115. The abbey had a great influence in the social and economic organization of a wide area and it owned several churches and castles near Cagli, Gubbio, Città di Castello and Senigallia. These possessions caused many conflicts with neighbouring Cagli which sacked and plundered the abbey on several occasions. The Prior of Fonte Avellana decided to put an end to the autonomy of the Benedictine abbey because of the growing secularism among abbots. In 1514 it joined the Bishop’s seat in Cagli.

Little is left of the original structure of the church because of the many restaurations that took place through the centuries, such as the as the hut-shaped façade which can be traced partly in the bell tower and on the left side. The shrine 's bell bears the date XXLMDCCCLVI . The interior has a single hall with low exposed trusses ; the high altar is a Baroque stuccowork and is devoid of the altarpiece. Interesting are the two rib- vaulted rooms beyond the high altar , having stone arches resting on low pillars, some with rounded corners and other on columns ; in the church we can also admire the seventeenth-century altarpiece representing the " Madonna of the Rosary and Saints " .