When you’re ready to move on, continue the tour with a visit to the Labyrinth of Porsenna.
This is a network of tunnels used during the Etruscan era as a water supply system that was later abandoned. The visit takes you inside a Roman cistern from the 1st century BCE, located right underneath piazza Duomo, and ends at the Torre Campanaria, previously known as the Torre Civica, from the 1100s. You can climb the tower (27 m., 142 stairs) to enjoy a view of the Valdichiana.
The Etruscan itinerary finishes with a visit to "La Città Sotterranea" Chiusi Civic Museum, which, with is exhibition routes, adds to the historic overview of the city with even more interesting artefacts.