The commune of Montalto delle Marche, after being a Farfa feud in the Middle Ages, was elevated to the rank of city, bishopric and capital of the Sistine territory in 1585, by order of Pope Sixtus V, a native of Grottammare who considered Montalto delle Marche his second home.

The entrance to the old town is still via the two perfectly preserved gates of Porta Patria and Porta Marina. Palazzo del Preside, built by Pope Sixtus V in 1587–88 as the seat of government for the State of Montalto, is in the main square and is now the town hall and home to the Musei Civici.

The museum complex has an archaeological museum that traces the various historical stages of Montalto and its hinterland from prehistoric to Roman times; the lovely L’acqua, la terra e la tela ethnographic museum, dedicated to rural civilization; the art gallery; the fascinating Carceri Sistine prisons with interiors reconstructed on the basis of a 1604 inventory and the narratives of prisoners’ lives, traced in historical records and brought to the stage by a theatrical company.

The Sistine history of Montalto delle Marche is documented by the Museo Sistino Vescovile, in the former seminary. In addition to the rich vestments with gold embroidery, belonging to the early bishops, there are paintings and wooden sculptures, and a thirteenth-century painted crucifix, with precious gifts from Sixtus V to his homeland, including the Reliquary of Montalto, a French masterpiece of goldsmithing. The cathedral of Santa Maria Assunta, begun in 1587, is opposite the museum.