After just 20 seconds in a dark, narrow underground tunnel, crouched down with no room to stand up, I was desperate for some air.
I was also totally in awe of the Vietnamese people who spent weeks on end underground to escape the American B52 bombers overhead during the Vietnam war.
Today the Cu Chi tunnels, near Ho Chi Minh City, are a major tourist attraction.
Tour guides point out the bomb craters, invite you to find the concealed tunnel entrances, and let you in on the tricks used by the Vietnamese to fool the GI’s sniffer dogs – they rubbed American tobacco and perfume round the tunnel entrance to camouflage cooking smells.
You can even opt to rattle off a round of live ammunition from an AK-47 rifle if the mood takes you.
But Vietnam has much more to offer than war relics.
Its lively, colourful markets give a good introduction to what the country is about today.
Ho Chi Minh City’s Cholon market – the name means big market – is a veritable assault on the senses.
Among its maze of stalls and narrow alleyways you will find everything from live chickens and Chinese lanterns to Tommy Hilfiger baseball caps.
Not to mention an amazing array of fresh fruit and veg – baskets piled high with garlic, buckets of pickled lemons, mounds of coconuts and stacks of dragon fruit – a bright red waxy globe with green spines which tastes like a kiwi fruit.
Around each corner you are greeted by a different aroma – incense, cinnamon, strong Vietnamese coffee – and you could spend the whole day people watching.
From early morning people gather in the public parks for Tai Chi sessions or rig up an impromptu badminton net for a quick prework match before the first of Ho Chi Minh City’s three rush hours set in.
This consists of wave after wave of mopeds, many with a family of four squeezed on to just one vehicle, or fashionably dressed women in smart outfits somehow resistant to the dust of the big city.
If you are feeling adventurous and want to get close to the action you can hire a cyclo, the Vietnamese equivalent of the rickshaw, ensuring you set the price first. In the capital Hanoi, everyone is an entrepreneur, having got the hard sell down to a fine art.
Each time I stepped out of my hotel, I faced a constant stream of streetsellers and by the time I’d got to the end of the road I’d splashed out on a map of Hanoi, a phrasebook, and 10 postcards – and spent about £3.
I probably could have got the bundle cheaper, but it was too hot to haggle with temperatures that topped 30C.
Having outpaced the persistent street hawkers, I made it to the old quarter of Hanoi, where the city’s narrow lanes are named after the goods that have been sold in them for centuries – Sugar Street, Silver Street, Cotton Street and Tin Street.
Here, there are countless bargains to be had, if you are prepared to play the haggling game, with goods including silk shirts, dresses, linen suits, wooden carved antiques and lacquerware bowls.
Alternatively, you could shop for something more modern and update your CDcollection with Vietnamese copies of Western hits.