The narrowest pass was crossed by means of a tunnel chiseled out of solid rock: a first tunnel apparently of the 3rd century BC was replaced by an adjacent tunnel by Vespasian. This is the modern "Gola del Furlo", the ancient name of which, "Intercisa", means "cut through" with reference to these tunnels. The modern 2‑lane road, the "SS 3 Flaminia", still uses Vespasian's tunnel, the emperor's dedicatory inscription still in place; remnants of the earlier tunnel can also be seen.