Part 3/16:
Hidden beneath the surface of Northern France, the Naours tunnel system dates back to the Middle Ages. Initially constructed as a refuge during conflicts, it became a hideout for Allied soldiers during World War I, who left behind thousands of inscriptions carved into the stone walls. The tunnels serve as a historical testament to the city's past.
Shanghai Tunnels, USA
Portland's infamous Shanghai Tunnels provide a window into a dark chapter of urban history. Built in the 19th century, these underground passages linked the waterfront to various businesses, hotels, and bars. Legends abound of their use in human trafficking, where unsuspecting victims were kidnapped and sold into forced labor on ships.