The tour begins on the first floor with a display of religious works telling the story of the Christian faith in the Valdelsa from the earliest days up to the establishment of the Diocese of Colle, with works of art from the churches and institutions of Colle and its hinterland. The first room houses the earliest examples of medieval art, including a large Maestà by the "Maestro di Badia a Isola", the work of an anonymous Sienese artist in Duccio's circle, a wooden Crucifix by Marco Romano, an absolute masterpiece of 14th century Gothic sculpture, and a splendid panel painting depicting the Birth of the Virgin attributed to Cennino Cennini, an artist born in Colle and heir to the school of Giotto. The rich silver eucharist set known as the Treasure of Galognano, dating back to the 6th century, was hidden in a sack during the turbulence and raiding that plagued northern Tuscia between the end of the Classical era and the early Middle Ages. The second room hosts 15th century paintings, while the third, which recounts the establishment of the Diocese of Colle, houses work by artists of the 16th and 17th centuries. The tour continues around the cloister to the large hall with its trussed wooden roof, which has been chosen as the ideal setting for showcasing works either commissioned by or formerly housed in the Cathedral of St. Albert and St. Martial.