The tour begins with a meeting with a guide at the collection point: the Green Line Tour Office, Via Giovanni Amendola 32. The first point of interest is Civita di Bagnoregio - a hilltop site threatened by erosion of the land and nicknamed "the dying city." To get there, you have to cross a 200-meter bridge from the nearest hill, straight to the gate of the historic center. With a population of just 11, the town is an unusual spot on the tourist map of Italy, and the number of visitors is under constant surveillance. Next is a visit to the province of Terni, in the Umbria region, to the city of Orvieto. It was an important Etruscan center between the 7th and 3rd centuries BC. Today it looks like a medieval city, but much of the Etruscan ruins are still preserved underground. Lunch at a local restaurant and a tour of the underground, where you can see Etruscan wells and cisterns. Finally, a panoramic walk through the center of the city, with typical medieval narrow streets, up to the famous Piazza del Duomo, with its imposing cathedral, the symbol of the city, considered a masterpiece of Italian Gothic architecture dating back to 1300. Return to the meeting point.