Jiucyudong Tunnel, China – This tunnel looks natural, but it was blasted through the rock formations of Taroko National Park in 1996.

Cu Chi Tunnels, Vietnam – These tunnels, built during the Vietnam War, reveal how the Vietcong were able to so effectively infiltrate the South before the Tet Offensive.

Tokyo Bay Aqualine, Japan – This bridge and tunnel combination saves motorists 45 minutes each way on the trip from Kawasaki to Kisarazu.

Laerdal Tunnel, Norway – This is the world’s longest roadway tunnel, and features subtle design elements to keep drivers awake over the 15 mile ride.

Chunnel, England and France – Perhaps the most famous modern tunnel is the Chunnel, which connects France and England under the English Channel.