Naples’ bustling city is often showcased along the Via San Biagio dei Librai, or Spaccanapoli, where narrow streets house stores and pizzerias. Here there are tours that take visitors through the tunnels built as water cisterns in ancient times. At the Duomo, there is a vial of blood said to miraculously liquefy annually that was the blood of Roman Emperor Diocletian. The blood is supposed to bring good luck, and in the 36-year period that it did not liquefy, the city experienced an earthquake and Vesuvius eruption, so let your kids be the judges.