Củ Chi Tunnels

During the Vietnam war one of the methods VC (Viet Cong) and NVN (North Vietnamese Army) used to attack American and other forces in and around Saigon were tunnels in the Củ Chi area.

red is the Cu Chi district

This is a very extensive tunnel system consisting of over 250KM of tunnels dug by hand in the earth around the province of Củ Chi. Because the earth is very firm no bracing was required to build them. A local name given to the ground in the area is "iron earth" because it is so firm. Holes and tunnels can be dug into it that will not collapse even without bracing.

the tunnel plan explained

The Cư Chi tunnels were built at several different depths. There were 3m, 6m and 9m deep tunnels. Most of the network was at 3m and was used to move fighters and weapons through out the province. At that depth there were also meeting rooms, first aid stations, operating rooms, communication and planning centers and munitions depots. The deeper 6m tunnels went to triangular shaped bomb shelters and the 9m tunnels went to escape routes such as exits below the surface of the Saigon river and traps for pursuers.

making my way through a tunnel

The tunnel guide gave the group the opportunity to pass through a number of tunnels. We started with tunnels enlarged for westerners and ended with smaller tunnels that were original size built for Vietnamese. I was able proceed through the "westerners" tunnel section in an easy crouch. In the original size tunnels I needed to be in a low crouch with my head down and back and shoulders touching the top arch of the tunnel or squatting on one leg the shin of the other leg flat on the tunnel floor and the leg bent sharply at the hip and folded at the knee.

We didn't venture into any of the even smaller tunnels described as one way routes that are small even for Vietnamese and "plug" tunnels that lead nowhere and are too small to reverse direction in once entered.

The one way tunnels were described as being a tunnel defense mechanism where a defender could be at the widened part of the tunnel and easily prevent advance of people through the tunnel. Anyone coming through a one way section would not be in a position to effectively fire weapons or defend themselves. The plug tunnels are meant as a method to trap someone without need for a defender ahead in the tunnel.

The Wikipedia article linked mentions infestations of many types of bugs in the tunnels. I didn't note any while there. A lack of bugs in general is something I've noted during my visit to Vietnam that is very surprising to me. With the exception of dragon flies and ants I have seen very few bugs anywhere I've been. I have seen some flies, their low numbers are notable because of the abundant trash, maybe three spiders, one LARGE cockroach and an inch worm.