The "Antichissima città" (Ancient city) slogan has remote origins, emblematically depicted in the communal coat of arms with the founder Saturn shown on horseback. The city's medieval history avails itself of a chapter of great importance dating to 728, when, according to tradition, the town was given by Liutprand to the growing Patrimony of St. Peter. The most eloquent images of the pre-Roman and Roman civilisation come together in Poggio Savorelli, visible from the Via Cassia, just a short distance from the ancient access gate to the town (Porta Franceta or Porta Vecchia), with the amphitheatre (dating to the Augustan age) and the small rock church of the Madonna del Parto (formerly an Etruscan burial ground and later a place of worship of the god Mithras), amidst a substantial series of rock tombs of the sixthfourth century BC, with wall niches, simple niches, chambers used as columbaria etc. The most important ones are marked on the outside by sculpted pediments. At the top of the knoll stands the Villa Savorelli, whose park holds the ruins of the so-called castle of Charlemagne, subsequently inhabited by the Anguillara family.

The amphitheatre, entirely dug out of the tuff, is quite dramatic. The small church of the Parto has also been excavated from the rock and its walls preserve the remains of frescoes of a primitive nature: Madonna and Child between two Saints; St. Christopher and the Child; Procession to Mount Gargano with interesting pilgrim figures.

In the historic centre, the cathedral attracts attention (dedicated to the Virgin of the Assumption). It is built in the Romanesque style, and was completely renovated in the eighteenth century. Inside, two Corinthian columns, incorporated into the pillars in the presbytery, bear witness to the ancient origins of the church. It has a remarkable Cosmati-work floor in the central nave. The church contains a fine early thirteenth-century canvas in the Byzantine style depicting the Saviour Benedictory. The altar in the ambulatory (behind the choir) dates to the sixteenth century and is dedicated to Pius V, former bishop of Sutri. There is a fine wooden statue of the Bernini school depicting St. Dolcissima, the patron saint of Sutri. Gloomy but atmospheric, the crypt probably dates to the eleventh century and has eight aisles divided by columns of various types with ornate capitals.

Of the other churches, it is worth paying a visit to San Silvestro, whose altar is made from an ancient sarcophagus. In a room in the old hospital, which also houses the Historical Archives and the Library, the small Museo del Patrimonium has been set up. In the first room there is a collection of exhibits from the Roman period to the early Renaissance: epigraphs, detached frescoes from various epochs and a tabernacle by the school of Andrea Bregno. The second room houses sacred vestments and the reliquary of St. Pius V (seventeenth century) and of St. Liberato (eighteenth century), and a nineteenth-century monstrance. It also contains the codex of the Lombarda Vulgata of the twelfth century. In the third room, we find paintings from the sixteenth century, a processional standard and a remarkable piece of Baroque embroidery (vestment for the Pontifical Mass of St. Dolcissima).

A short distance from town, an ancient fifteenth-century monastery that stands in a park known as the "Oasi di Sapientia" has a surprise in store for visitors, in the form of an unusual collection of minerals in their unpolished state from every part of the world (rubies, aquamarines, topazes and diamonds).