Crypta Neapolitana

The Crypta Neapolitana[1] (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.

Entrance to the Crypta Neapolitana from the Naples side.
Western, Fuorigrotta end
Serino Aqueduct entrance

The tunnel connected Naples with the so-called Phlegrean Fields and the town of Pozzuoli along the road known as the via Domiziana.