Crawl through a notorious brick-lined tunnel system in a historic Florida neighbourhood. Open a window into the lives of elite Greek families in Naples, explore a three-story underground city in Iran, and find 2nd-century barracks buried in Rome.

Walk the service tunnels hidden beneath Emperor Hadrian's lavish villa in Italy. Uncover a chilling mass grave from the Thirty Years' War in Germany, find the foundations of a Roman basilica in London, and glimpse Neolithic life on a Danish island.