OK! I really don't know what you guys are thinking, hehehhe.... here am talking about the famous Củ Chi Tunnel in Saigon, Vietnam. The Củ Chi tunnels were the location of several military campaigns during the Vietnam War.
From Wikipedia :
The 75-mile (121 km)-long complex of tunnels at Củ Chi has been preserved by the government of Vietnam and turned into a war memorial park. The tunnels are a popular tourist attraction, and visitors are invited to crawl around in the safer parts of the tunnel system. Some tunnels have been made larger to accommodate the larger size of Western tourists, while low-power lights have been installed in several of them to make traveling through them easier and booby traps have been clearly marked. Underground conference rooms where campaigns such as the Tết Offensive were planned in 1968 have been restored, and visitors may enjoy a simple meal of food that Viet Cong fighters would have eaten.
It's amazing how small they build this in order to avoid the western from coming in. When you are pushed to the edge, survival is the priority in life.