There’s not a lot of wriggle room on the little tourist train to The Iguazu Falls, which might explain why the chap opposite and I fall easily into conversation, given that my knees are nestled between his thighs. A retired naval officer with a booming basso profundo voice, military bearing and a large grey beard, he tells me that this is the first year he has had the courage to travel alone after his wife died 4 years ago.

”Don’t forget to take pictures together, as suddenly you blink and there’s only one of you left.”

All of our pictures after that are of us clinging desperately to each other, in case one of us tips over the edge into the waterfall.

At a lunch of spinach empanadas I look at the photos and wander with salutary sadness which one of us will go first, unless of course we go together in a blazing plane crash over the Andes; one of our images like an absent ghost haunting whoever is left with the memory of that casually thrown arm, the proximity of that beloved body. I’ve fallen into a existential funk; thanks a lot, beardy man.

But a high speed rib trip in the afternoon banishes all thoughts of death as apart from one adolescent boy channelling supreme indifference befitting a teenager, even with a gazillion tonnes of water pummelling his scalp, the rest of us including his dad scream and laugh like banshees as the boat thumps and bounces across rapids, advancing right into the waterfall, soaking us all completely, the water so dense that I start panicking between gulps of laughter as I can’t catch my breath. We emerge completely sodden, deliriously happy, the joy of being alive pulsing through our veins.

The Iguazu falls are one of the three largest waterfalls in the world and once again impossible to convey in a photo. A million and a half litres of water per second falls from a stretch of 3 km, you can see them from both sides, Brazilian and Argentinian. Having seen them from both I agree with the adage that the Argie side is the stage while the Brazil side is the show. The queue of cars full of Brazilians waiting to get through passport control is because like us, they find the cost of shopping and filling their cars with petrol on the Argentinian side much cheaper. Taxis and tour groups don’t have to queue so we fly through. Everywhere we go we are surrounded by butterflies, some have a huge wing span and look like birds. Weaving their way in and out of the waterfall spray the Great dusty swifts are unique to the falls, nesting behind them.

In the evening we do a bike ride organised by the hotel. After about a km I screech to a halt as there is a 4 foot long red, black and white striped snake cooling on the road in front about to be squashed by my front wheel. As it slithers away into the subtropical rain forest Marc our guide says it is a rare False Coral, the real Coral being the deadliest snake around here and much more common. Pondering that it could have been much worse since the razor sharp saddle is engulfed somewhere between my buttocks, and resisting the urge to continue cycling with my feet on the handlebars, several motorcyclists then whizz past us, the bikes loaded with boxes.

“Contrabandos” Marc tells us – smugglers, taking wine to Brazil, and chickens “sometimes with extra inside” (ie. Cocaine) to Argentina.

We return to our room to find that none of the clothes soaked on the waterfall trip have remotely dried, unsurprising in 80% humidity. Clive has crotch rot from his cheap nylon shorts which now weigh about 10kg wet, and well, my voluminous pants are now as heavy as lead. Damp stuff starts smelling real bad real fast, so the pants and the shorts are bin bound. I now have 6 pairs left, not counting the flimsy, useless ones I forked out a tenner for in BA, which may do well as headbands actually. I will have to start copying my youngest nephew whose pants MO on holiday is to wear them front-ways, back-ways, inside out, front and back. Quite disgusting, but needs must. Thanks Angus.

Tomorrow – Salta.