The ancient city of Sutri stands on a tufa cliff on the border between the Sabatini mountains to the south and the Cimini to the north, surrounded by the Promonte and Rotali rivers. Belonging to the ancient Falisco area, it was from the 5th-4th centuries BC that Sutri took on considerable historical and strategic importance as the gateway to the Agro Falisco and inland Etruria. The most important monument in the area is without doubt the amphitheatre, carved into the tufa and located in front of the city. Limited in size (49.60 x 40.80 metres), it has two entrances: one overlooking the via Cassia, now in ruins due to the collapse of the access gallery and steps, the other, higher up, with a covered walkway. The cavea consists of three tiers of seating, bordered by corridors called "praecinctiones". The lowest order was reached by four staircases (vomitoria), there is a rectangular niche, probably intended as a box of honour. In the middle cavea, and still clearly visible, there are eight boxes with seats at the bottom, which were accessed by as many ramps. Two of these bear evidence of a channel for conveying rainwater. The upper cavea was accessed directly from the steps, with two staircases of recent construction. To the north of the latter, a baldric on which the remains of half-columns of Tuscanic order in relief are visible. The dating of the monument is rather difficult, in the absence of historical-epigraphic clues, but the essential and unadorned architectural layout can be assigned to the last decades of the 1st century BC to the first years of the 1st century AD.