Just behind Piazza Tasso, a stunning natural phenomenon is on view from Via Fuorimura. Il Vallone dei Mulino is a deep mountain cleft that dates from a volcanic eruption 35,000 years ago. Sorrento was once bounded by three gorges, but today this is the only one that remains. The valley is named after the ancient wheat mills that were once located here, the ruins of which are still clearly visible.
