Saigon - Half Day Cu Chi Tunnels Tour by Bus - Ben Dinh Tunnels is Cu Chi Tunnels - an underground tunnels network constructed by Vietnamese fighters during the struggle for independence. It took about 25 years to build this underground city, which has living rooms, kitchens, hospitals, weapon factories, storage facilities and command center. The tunnel system was an excellent way for the Vietcong to move around the countryside undetected by the Americans and home to around 10,000 people who lived underground for several years. You should visit Cu Chi Tunnels Historical Monument to understand what the protracted and arduous struggle is.