The Cu Chi Tunnels were vital in sustaining attacks from US forces during the Vietnam War. CAROLYN BOYD goes into the underground network to discover how so many lived, fought and died defending their country.

An AK47 cracks in the distance as the smell of burning wood wafts under my nose and people close in around me. Forty years ago this scenario would have been a terrifying prospect for, on this spot, the Viet Cong and Americans were bombing and shooting the hell out of each other. Now, however, my biggest threat is the encroaching crowd of tourists. I’m trying to maintain my vantage point as our guide, An, shows us around the Cu Chi Tunnels, just outside Ho Chi Minh City in the south of Vietnam.

The tunnels were originally carved out of the hard, red earth by the Viet Minh in the war against the French in the late 1940s but in the late 1960s they were re-excavated by the Viet Cong. This allowed them to take control of a huge rural area just 40km from Ho Chi Minh City, or Saigon as it was then called. Some of the tunnels even ran under the American base and as our tour goes on, it becomes increasingly apparent that the tunnels allowed the Viet Cong to be very clever in their fighting tactics.

After watching a video in the visitor centre, An explains – with the help of a model mounted on the wall – that the underground network of tunnels totalled more than 250km and that they allowed communication between the different pockets of Viet Cong, who were divided by South Vietnamese and American bases. They were essential to the Viet Cong’s attack on the US Army and they also gave shelter to civilians from the chemicals and bombs raining down above ground.

The people of Cu Chi lived underground for as long as 10 years. Couples were married, babies were born, children were raised and elderly people died as they lived like rabbits in a warren. In the forest outside the visitors’ centre, there are several dug-outs that reconstruct how the people would have lived. Inside, the authentically dressed mannequins are fixed in poses that demonstrate various people’s tasks – from cooking, to clothes-making – and they give you an idea of what life was really like.

While the people remained hidden underground they had to be careful to not give themselves away to the B-52s flying overhead. As An leads us into a dark corner of woodland, I spot tiny wisps of smoke filtering out of the ground. Smoke from campfires was a giveaway to their whereabouts, so to get around this they covered the chimney, located several metres from their camp, with a flat vent so the smoke would leak out gently around the sides, rather than rise up in one plume.

Food was also very limited and for 10 years the people lived mostly on cassava root and rice. At one of the dug-outs, another Cu Chi guide gives us a piece of cassava to try. It’s bland and starchy, not something I can imagine eating for 10 days on the trot, let alone 10 years.

In other dug-outs there are mannequins demonstrating how the Viet Cong made their weapons. Faced with a lack of their own resources, the Vietnamese recycled the metal from B-52 bomb shrapnel into huge nail-like rods, which, when planted in a variety of wooden frames and hidden in holes in the ground, hurt, maimed and killed many of their American enemy.

There are all sorts of contraptions and traps on display – some designed to lacerate soldiers’ legs, others simply swallowing them into the ground into a tomb of metal spikes. Bravely, An sticks his smartly shoed foot into many of them to demonstrate how they worked, quickly jumping out before they too swallow him up.

If the traps didn’t get the Yanks, then the gunfire almost certainly would have. As the American soldiers stalked their enemy through the woods and jungle, the Viet Cong could pop out of their underground hideaways via a tiny trap door, open fire with a shower of bullets, then disappear back underground in a matter of seconds. The size of the trapdoors is astounding – just 30cm by 50cm – and, as members of our tour group try and wriggle their beer bellies through the narrow opening, An jokes that: These days McDonald’s would stop them from winning the war.”

It wasn’t long before the Americans realised the tunnels were giving the Viet Cong a huge advantage over them and so, when showering chemicals from the sky failed to wipe out enough of the enemy, the Americans sent in their own troops. These ‘tunnel rats’, as they were nicknamed, sustained horrific casualties as they tried to squeeze into the tiny subterranean spaces. So, instead of risking more lives, the Americans brought in German Shepherd dogs to sniff out the enemy.

Under a tiny rock, An points out one of the air holes from a tunnel and tells us how the Vietnamese remained one step ahead of the dogs. They placed American tobacco around the tunnels’ air holes, so the dogs merely sniffed out their owners’ scent instead of the enemy’s.

While An’s explanations and the reconstructed dug-outs go a long way in giving an insight into the war that raged here for several years, none of this compared to actually being inside the tunnels. Through a narrow, rectangular hole in the ground I descend into the earth and have to bend my knees and dip my head to fit in. It’s hard to believe people were able to stay here for any length of time, let alone fight here. And although the tunnels did give the Viet Cong an advantage over the Americans, just 6000 out of 16,000 fighting in and from the tunnels survived.

Tourists have the advantage of electric lights showing the way through, so it’s even harder to believe they did it by candlelight or in the dark. The space is minute and I can barely amble through. As the panic sets in, I wonder just how it will take to get to the other end.

Thankfully it isn’t long before the daylight creeps in and an exit appears. As the AK47s continue to crack in the distance, I’m glad they’re not aiming at me. •

• There are several companies in Ho Chi Minh city offering tours to the Ben Dinh Tunnels, starting from around US$4. Opodo (0871-277 0090) have return flights with Cathay Pacific (via Hong Kong) into Hanoi and out of Ho Chi Minh City from £730 per person.”