
Uncovers the extraordinary worlds that exist beneath major urban centers, from the tombs and wartime shelters of Naples to the manmade Royston Cave in Hertfordshire, England.

Old Tombs, buried coins, and a 4,000-year-old oak log coffin are discovered.

A buried ship, wartime cellars, jar burials and mass graves are excavated.

Explorers find a tunnel system, mass graves, city foundations, and longhouses.

Explorers discover tunnel systems, a sprawling city, and military barracks.