The Cu Chi Tunnels are definitely worth the day trip out of Saigon, to see it is better than you could ever expect having heard about them back home. Just 70km (40 miles) northwest of Saigon, the Cu Chi area lies at the end of the Ho Chi Minh Trail and was the base from which Vietnamese guerillas used to attack Saigon. As a result, the whole area became a "free-fire zone" and was carpet-bombed in one of many American "scorched-earth" policies. But the residents of Cu Chi took their war underground, literally, developing a network of tunnels that, at its height, stretched as far as Cambodia and included meeting rooms, kitchens, and triage areas -- an effective network for waging guerrilla warfare on nearby U.S. troops.