I’m being ushered down a gangplank on the darkest of nights, one devoid of stars and surely impossible for even the most
avid carrot-eater to adjust their eyes to.

My apprehension is captured in the gaze of a torch-bearing boatman, who steadies my stare as I clamber on to his 25-seater craft in Leticia, Colombia’s most southerly city.

A frontier settlement of sorts, Leticia sits on the border of Peru and Brazil to create South America’s Amazonian triangle. The area is known as ‘the lungs of the earth’, thanks to its being responsible for 20 per cent of the world’s total oxygen supply.

The Amazon does trickle into Colombia, but I want to explore its upper tributaries so I can delve deeper into the world’s most species-rich tropical rainforest. Hence the boat trip – a necessary evil that’s taking me 10 hours southwards, towards the murky waters of Iquitos in Peru, the largest jungle-locked city in the world.

I try and focus my excitement on Iquitos – the destination, not the journey – as our snug, petroleum-scented vessel speeds down river.

As the first streaks of a russet dawn stain the sky, I spot small communities congregating on the roofs of their rain-soaked abodes. It’s the worst Peruvian flooding in 22 years and I am in deep.

Into the wild

Some cities I instantly fall in love with for their high-octane, 24-hour madness. New York, Bangkok, Cartagena and Buenos Aires are up there with the best of them. Iquitos, sadly, is not.

It’s got all the mayhem – thick blankets of smog roll into every corner of town, while spluttering Latino-style tuk-tuks thunder past at frightening speeds all night long – but no soul.

Like an overdose of Marmite, I just can’t stomach it. Fortunately, I’m not here to loiter.

I gratefully disembark and meet my guide, Jorge, a native of the Yanamono region of Peru. We slip out of the smog-fest without looking back, and head 70km south to where the river meets Rio Yanayacu, a tributary on which our base camp sits.

The ride is peaceful and pacifying after the urban swirl, and my tiredness dissipates at the thought of the wilderness that awaits.

Hopping out on to an elevated gangway with stilts, I learn our rustic lodgings are perched immediately over a piranha-infested swamp. Sleep walking or taking a nighttime dip, therefore, is not advisable.

Neither is a preoccupation with technology; there’s not a wifi connection or phone signal to be found, just hammocks, books, games and the ever-present rustlings of life in the jungle.

It’s strangely comforting, as confirmed by Jorge, who declares: “If the jungle is silent, be cautious. It means an anaconda is nearby.”

After we’re greeted by local Peruvian tour company Maniti Expeditions’ beaming, personable hosts, we head off to a small estuary in a rowing boat in search of caimans (a sort of South American alligator) and one of the world’s largest freshwater fish, the paiche.

At more than five feet long and sporting devil-red scales, these bad boys look as if they would gobble you up the second you slip overboard. But they’re actually timid creatures that simply have a good appetite.

“It’s the piranhas you need to look out for,” grins Jorge. At first glance, these small black fish, the Amazon’s best-known scavenger, don’t look like they’d put up much of a fight. On cue, Jorge wiggles his bamboo fishing rod and a piece of bait in the dark waters around us.

A frenzy of scales and flashes of razor-sharp teeth erupt in the shallows. “If you’ve bloody cuts or it’s your ‘lady time’,” says Jorge a little awkwardly, “don’t fall in or put any body parts in the water”. Got it.