Sutrium: town in southern Etruria, modern Sutri.
Later, Sutrium was recognized as a Latin colonia; its citizens belonged to the Tribus Papiria. The city, which commanded the Via Cassia, played a role of some importance during one of the civil wars, the Perugine War of 41 BCE. Under the Empire, it was known as the Colonia Coniuncta Julia Sutrina. It is interesting to know that an ancient mithraeum was later reused as a church, the Madonna del Parto.
Today, the amphitheater is the most spectacular monument; its arena measures about 50x40 meters. There's a necropolis next to it. The remains of the ancient walls can be visited; the modern Piazza del Comune is on the site of the ancient forum, and a small bathhouse has been identified.