Armed soldiers let us into the park again on our final day. After a nasty burn on my face, neck and shoulders from the day before, I was hiding under a long sleeved black top, long black trousers, sunglasses and a hat and with a blue towel wrapped over my nose, around my cheeks and knotted behind my neck. The German man in our group asked me to pose for a photo so he could tell his friends that he’d met an actual FARC guerrilla. I even swam in the Caño Cristales river in the full outfit (including the hat), which made the “you look like a terrorist” joke even funnier; the heavy towel wrapped around my nose and mouth in the water gave me the sensation of being waterboarded.

This was easily the most beautiful day on the trip. The Caño Cristales river passed through a series of water falls, tunnels, channels, lagoons and rapids, and, of course, over blankets of the blooming plants, like red, underwater cotton fields. We also had to do a couple of refreshing river crossings, carrying our bags over our heads.

With increased beauty came increased opportunities for photos, with our guides patiently waiting for us to take each one. Yes, memories are important. But my fixation on capturing them on film was still kinda sad.

Our guides told us of two local myths. One was that if you eat a live sardine, you learn how to swim. The other was if you eat a live lizard, you’ll learn how to play the guitar. They also showed us a place where people used to go cliff diving into a pool until a young girl broke her back doing it. They were able to drag her out of the water, but the banks were steep and there was no way of getting her to a car. They had to wait for a military helicopter to winch her up. So, swimming’s not allowed there any more.

The final attraction was a wide patch of river called the “red carpet”, covered with the reddest, richest plants we’d seen. We took our pics and walked back towards our waiting truck. Back at the hut with the beer and snacks, everyone was in a party mood. There was a sense of accomplishment, and we were all chatty. Next to us, some Americans were being taught about the referendum by an Argentinian tourist. And around us, a dozen soldiers with assault rifles and night goggles stood, watching us eat and drink.

I’ve written before that “Colombia’s tourism industry reminds me of a retired soldier who makes his living by selling exotic fruits in a freshly repainted concrete shelter that was recently used to torture insurgents”. Next to Colombia’s awesome (and I mean that in every sense) natural environment you’ll find a dark history. The Caño Cristales river is no different.

The war. Since the 1950s, Colombia has been at war with itself. Marxist guerrillas of the Che variety have been fighting the government since a political assassination in Bogotá sparked “La Violencia”. At first, their fight was spurred on by Colombia’s ultra-conservative politics, and that leaders of the left kept being assassinated. Up until just a few years ago, Colombia was the most dangerous place on earth to be a union leader. And, of course, they were pushing back against the meddling USA, who were every bit as awful here as in every other South American country.

Fighting on both sides displaced hundreds of families in the Andes. They travelled south into the Meta region, eventually constructing La Macarena, the town next to Caño Cristales. By the 1970s, the Marxist ideals of the rebels’ founders had given way to a fight for survival. Colombia’s drug barons had shown how you could make a huge amount of money from isolated, rural land – the same land they were fighting on – by growing coca.

The initial “desplazados” (displaced people) were already using slash-and-burn tactics to clear farm land to make a living. Coca crops offered these economically-excluded communities an even better income, but the guerrillas also wanted a piece.

The government had been somewhat ignoring the peasant farmers and their coca production out here in the wild, but they couldn’t let those plants start earning for the revolutionary army they were fighting. So, for many years the government used “glyphosate fumigation”, now thought of as a carcinogen, to destroy the crops in a process that is to nature what napalm is to small Vietnamese villages.

There have been efforts to “manually” eradicate crops (ripping/burning by hand) instead of spraying, but it’s much more dangerous. In late 2005, FARC guerrillas killed Colombian security forces near the park through which Caño Cristales runs. In retaliation, the government announced they’d be stepping up their coca eradication campaign in the area, which began in January 2006. To protect their crops, FARC followed their mantra of “when life gives you lemons, kill a lot of people”, until the government announced that spraying from the air would begin again.

Thankfully, it looks like peace has made it possible to manually destroy crops without too many people losing their lives. That environmental tragedy has mostly stopped in this region – which is great for local wildlife.

Anyway, so, the threats to this national park are many. First, you have displaced families trying to get by, illegally settling and clearing the land to farm on. Then you have the war with guerrillas and narcotraffickers, which keeps the national military from effectively policing the park to stop the farmers. Third, there’s the government’s own efforts at coca eradication via fumigation, which pretty-much kills everything. And fourth, you can now add black tar sands to the mix, which will be far more enticing to investors once the war ends.

Driving back to town, we passed abandoned, jutting concrete structures that were once intended to be part of a military highway that was never finished. Hopefully a Yes vote the following week would mean there’d never be a need for such a thing. The war would be over. The government could get back to protecting the land. Tourism could increase. Disarmed soldiers could start working in the tourism industry. Coca farms could be dismantled peacefully, without fumigation. So much hinged on this vote for these rural areas.

That evening we were back at the restaurant chatting to the german couple, who I’ve decided to call Hanz and Freida, two solid German names. Hanz noted that in Colombia you find all sorts – Africans, negros, blacks, coloured people and Indians. No joke, he said all five of those words, like he’d just picked up a racist thesaurus. I pointed out that the revolutionary army Bolivar commanded to overthrow Spanish rule in South America was mainly black, as 5 million slaves had been brought by Europeans through Cartagena, so it may not be that surprising to find people of colour here.

Mum added that cultural diversity in Colombia is no different to, say, London. “I know,” Hanz seemed to lament, “they are all coming to Germany now, too. Germany is changing.” This was so disheartening. He even said he was a journalist. Perhaps for the German version of Town and Country. (I googled him later. He works at the German radio version of the BBC. He covered general interest regional stories. I assume the biblical flood of immigrants coming to Europe counts as a regional interest.)

Our guide came and told us the flight was leaving early to avoid the afternoon rain. 30 minutes later she came back to tell us it was flying at the normal time. Hanz harrumphed, his head cocked back, his eyes looked up to the heavens. “I don’t know,” Frieda said, “it’s different here than in other countries.” I looked down, noting on my phone that the couple often rolled their eyes at inefficiencies, tutted and muttered when things weren’t German, and were generally judgmental, insulated twats.

I could feel every inch of my burned face and neck tightening. I’d grown my own red carpet of dying skin. Or maybe I was just angry.