Cu Chi tunnels, Vietnam
One of Vietnam's most interesting war-era attractions is found near the town of Cu Chi, about 40 miles outside of central Ho Chi Minh City. A network of tunnels used by Viet Cong forces until 1975 are now open for tours. Visitors can enter a small portion of the original complex, which, at the peak of the Vietnam War, included tunnels that together measured about 120 miles in length. The passageways were only 2 to 3 feet in diameter, but there were also underground barracks, command centers, and even mess halls and hospital operating rooms. Today, visitors can crawl through sections of the original tunnel (some of which have been widened slightly to accommodate more tourists).