Crypta Neapolitana
The 464th longest tunnel in the world
The Crypta Neapolitana (Latin for "Neapolitan crypt") is an ancient Roman road tunnel near Naples, Italy. It was built in 37 BC and is over 700 metres long. The tunnel connected Naples with the so-called Phlegrean Fields and the town of Pozzuoli along the road known as the via Domiziana.
Tunnel data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).