Terni is a city in the southern portion of the region of Umbria in central Italy. The city is the capital of the province of Terni, located in the plain of the Nera river. It is 104 kilometres northeast of Rome and 81 km south of the regional capital, Perugia.
The Latin name means "between-two-rivers", in reference to its location on the confluence of the Nera river and the Serra stream. When disambiguation was needed, it was referred to as Interamna Nahars. Its inhabitants were known in Latin as Interamnātēs Nartēs.
Interamna was founded as an Ancient Roman town, albeit settlements in the Terni area well precede this occurrence. During the 19th century, steel mills were introduced and led the city to have a role in the second industrial revolution in Italy. Because of its industrial importance, the city was heavily bombed during World War II by the Allies. It still remains an industrial hub and has been nicknamed "The Steel City".
Terni is also known as the "City of Lovers", as its patron saint, Saint Valentine, was born and became a bishop here, and the remains are preserved in the basilica-sanctuary in his honour.