It's only seven in the morning and I'm already sweating profusely as I wait for a tour van to the Cu Chi Tunnels. Gawking at the energetic life around me, I'm struck by how Vietnam's biggest city, Saigon, is everything you hear it is: bustling, muggy, beautiful and packed full of scooters. But the longer you stay here, the more you're overwhelmed by the shadow of the war, which is forcefully cast down every one of Saigon's busy streets. Military vehicles are peppered across most of its empty spaces; choppers, tanks, jeeps, mortars. They are constant reminders, along with a frankly insane number of national flags, that the American Aggressors were sent packing, leaving behind a unified Vietnam.

'Unification' is the overriding theme across all of Saigon's museums and historical tourist attractions -- the aptly named Unification Palace probably the most obvious among them. It was at this palace that, in an act that marked the end of the war in 1975, Northern forces drove a tank through the front gates, claiming it back from the defeated 'Western puppet government' of South Vietnam.

Taking stories like these at face value, you'd be forgiven for thinking the end of the war was a happy occurrence for all Vietnamese people. And, thanks to decades of a communist regime pushing the state-sanctioned version of history, that seems to be true for most, particularly the younger generations. But for the Southern Vietnamese old enough to remember, the end of the war marked bitter defeat.

Not that they can openly tell you as much.

'People have to have secret meetings to be critical of the government,' says my tour guide, Tiny Tim, as he packs the tour group into the van.

'I know people who have been caught at these meetings and taken away.'

'Tiny Tim' is a nickname he'd picked up years ago from Australian tourists.

I'm now bouncing in our air conditioned tour van alongside a million scooters on a main arterial out of the city. As the urban expanse gives way to lush green fields, Tim starts to tell us about what to expect on this tour to the Củ Chi Tunnels. He's loud and proud and his accent has the hint of a Texas drawl.

The Củ Chi Tunnel system is one of the biggest tourist attractions in South Vietnam. It's also one of the more obvious when it comes to the regime's agenda.

About an hour and a half from the centre of Saigon, the 121km tunnel system was built covertly by the Củ Chi people to escape the horrors of the French occupation back in the 1940s. They later used it during the war to combat the Southern army and the Americans from within.

The tour van pulls up next to a dozen others and Tim swiftly escorts us through a security checkpoints onto the tunnel grounds. We're now ambling down well-worn paths in the Củ Chi jungle as Tim explains how the tunnels were used to combat the enemy.

'The Củ Chi fighters use what they call guerrilla tactics,' he says.

The fighters would pop out of tiny hatches along their secret tunnels and pick off a few enemy soldiers with their rifles before disappearing back into their underground labyrinth. During the war, the entire tunnel system was operated like an underground town. Dotted along the system were a series of underground chambers - bedrooms, makeshift hospitals, kitchens - where Củ Chi fighters could remain hidden from bombing runs for days.

As masters of the Củ Chi jungle, they also deployed a series of DIY traps, which they gave incredible names like the 'rolling leg slicer' and the 'director's chair'. As he demonstrates how these traps were used, Tim tells us he's supposed to explain just how many hundreds of soldiers they ensnared or killed. He's skeptical of this instruction, though.

'I don't think the traps really killed that many people,' says Tim quietly.

'I think these were more like scare tactics.'

We reach the last in the series of trap exhibits. This contraption is hung from the top of an empty doorway, dangling about one foot off the floor. It's hinged in the middle and spotted every few inches with large metal spikes.

Tim mentions this is his favourite trap to demonstrate.

'When American fighters would enter the room, the trap would come down like this,' Tim says, swinging the diabolical trap through the empty doorway.

'But your reflex to protect yourself makes you do this,' says Tim as he holds his hands up in front of his face. This stops the top half of the trap, but causes the hinged and spiked bottom half to come swinging upwards towards his crotch.

'And then, no more children for you. You become a ladyboy and you move to Bangkok,' he says with a cheeky smile.

The Củ Chi fighters have since been immortalised by the regime as heroes for their part in the war. It's a fact the tunnel attraction organisers make sure you remember. Before leaving, all visitors are made to watch a scratchy documentary; all black and white and edited like an American PSA from the 50s. The narrator quantifies the ingenuity and bravery of the Củ Chi fighters with just how many American soldiers they had killed. We're told one Củ Chi woman was the most heroic of all, apparently having taken out hundreds by herself.

As we emerge from the cinema room some half an hour later in a bewildered state, I see Tim watching us with a knowing smile.

'And how was the propaganda?'

We're in the van on the way back to Saigon, tearing down country highways at an alarming speed that is the Vietnamese norm. In the front seat, Tim seems to be in a contemplative mood. He begins to give more and more away about his experience of the war.

Tim grew up a Christian in the North. Once the war broke out, his family, along with the wider Christian community, were forced to flee to the South and start a new life on the banks of the Mekong Delta.

At the end of the war, Tim narrowly avoided a sentence in one of the North's internment camps, instead starting a long career as a school teacher.

In the state-sanctioned version of the story, these internment camps were actually 'reeducation camps', or trại học tập cải tạo. They offered you a chance at redemption, to be transformed into an upstanding comrade in the new, unified Vietnam.

The historical record, on the other hand, speaks of the hundreds of thousands of Vietnamese loyal to the South who were subjected to intense political indoctrination and forced into hard, often dangerous physical labour, such as sweeping or clearing active minefields.

Our arrival at my hotel punctuates a long silence. Tim had long since finished his story. I hop out of the van and awkwardly attempt some kind of farewell. Thankfully, Tim simply smiles from the passenger seat. His goodbye perfectly captures the conflict of travelling in Vietnam.  

'Yes, we are now communists, but we are also a free market. We have to make money. It's what you call a paradox,' says Tim, waving an authoritative finger out the window at me.

'Now, first round is on you.'