The camp was dark save for the fire and the more muted glow from a tablet about to reveal the secrets of the forest. We crowded over images – covertly captured on camera traps in jungle barely trampled on by human feet. On the screen, the mammals and birds of this remote Laos forest flickered into life: stump-tailed macaques, a silver pheasant, a snuffling sun bear, an Asian antelope, an Indian mongoose, a couple of sambar deer, and a pair of white spectacled Lao leaf monkeys. This photographic bounty was an animal jackpot up here in sky-scraping terrain on the Laos-Vietnam border.

The Nam Et-Phou Louey national protected area cloaks 4,229 sq km of mountainous jungle in off-the-beaten-track north-eastern Laos and shelters a handful (between 10 and 25) of endangered Indochinese tigers, five other cat species (leopard, clouded leopard, Asian golden cat, marbled cat and leopard cat), white-cheeked gibbons and Asian black bears, civets, porcupines and 288 species of birds. It’s a rich animal oasis in a country known as a linchpin in illegal global wildlife trafficking. Its reputation for being a source and a transit point for tiger parts and elephant ivory makes for very unsavoury reading and is being discussed at the Illegal Wildlife Trade conference being held in London this week (11-12 October).

Yet, up here on the slopes of Mount Forever (Phou Loeuy), the Wildlife Conservation Society is marrying animal conservation with ecotourism in a bid to ensure the survival of the last remaining band of Indochinese tigers in Laos, and other rare Asian animals.

I signed up to a five-day Cloud Forest trek organised by WCS guides and local Khmu villagers that would see us summit Mount Forever (Laos’ third highest peak at 2,257 metres), stake out a salt lick and observation tower, collect memory cards from the eight camera traps we would pass in the park, and end the trek sleeping in suspended bamboo baubles in a forest clearing.

At Navane village, where the 40km trek begins, I met local guide Puangsone, deputy village chief and a former hunter who told me he gave up hunting “as that only benefitted myself whereas ecotourism benefits my entire village”.

After a night spent with a Navane family sharing kao tom (purple rice and peanuts wrapped in banana palm) and mushroom salad, we set off along a dirt track, live cockerel in tow (to eat later), accompanied by marigold butterflies and the shrill call of the green-eared barbet bird. Ferns and bamboo sprouted wildly and the higher we climbed, the more monstrous the size of the moths became.

Then, after seven kilometres and at 1,000 metres, Khamphew, one of our guides, revealed one of the best things about this trek: cascading spring water that collects into pools. At Tad Ang waterfall, overlooked by banana fronds and glistening fernery, I stripped off and cooled down in the clear water, bathing separately from the male guides, according to Lao cultural mores.

At Houey Kaneng, our first camp, we cooled off in another stream before gathering around Khamphew as he readied his tablet. Waiting for the animal portraits to emerge, I asked Puangsone about the rice offering he had placed on the wooden spirit post, close to our campfire.

“When we arrive at a strange place, we have to ask the owners of this place to protect us and wish us luck. I offered the rice to the forest spirit here so that bad luck does not befall our lives.”

As the animal shots downloaded onto the tablet, it broke the suspense. The tigers had eluded the cameras but there were beautiful tableaux of macaques and spectacled leaf monkeys with their dazzling facial markings.

After a meal of rice cakes and eggs, and feeling secure that the spirit would protect me from any roaming animals, we settled down to sleep in the stilt huts of Houey Kaneng, built especially for the WCS trek.

Woken early by the choir of birds, we set off the following morning into thicker ground working our way around gnarled liana knots, our path decorated with white and orange orchids. Under a perfect blue sky, we began the ascent.

Below us, a sea of tree tops undulated in the breeze. Ahead, velvety moss-dressed trees lined our hike up a rocky staircase of jet black stones. It felt thrilling to trek where few had trodden before, accompanied by chattering birds all the way.

At the summit of Mount Forever, surrounded by dainty white orchids, Khamphew told us the US military had a base up here before the Pathet Lao communist victory in 1975. In an attempt to contain the “red tide” of Communism in south-east Asia and stop Laos becoming, in US military parlance, the dreaded domino, a secret war was conducted in the country. Between 1964 and 1973, nearly three million tonnes of bombs, rockets and shells fell on Laos. Up here on Mount Forever, we found discarded oil drums, ammo boxes, and spent mortar rounds.

It had taken seemingly forever to summit Mount Forever; was that how it got its name, I asked? “No,” Puangsone, said, it was because during the secret war there were 50 families who were afraid of the bombing. They believed the spirit of Phou Louey would protect them if they sacrificed a black and a white buffalo.

“They went to the mountain to make the sacrifice so they are protected forever but those families never came back so they are gone forever …”

On the fourth and final night we stayed at the Poung Nyied salt lick camp, 12km from the end of the trek. Here in the middle of the forest six spherical bamboo sleeping pods – the “nests” – are suspended in the trees. Designed by UK/Cambodia architect Atelier Cole in 2016, they look like giant Pac-Mans skulking in the branches but their bauble shape is actually inspired by the pretty paper lanterns on sale in the night market in Laos’ former royal capital of Luang Prabang.

Close to the pods is a simple, sleek observation tower, also designed by Atelier Cole, overlooking the natural Poung Nyied salt lick. As we climbed up the steps into the tower we received strict instruction not to make a sound, waiting to see if any animals would mosey in to suck up minerals. A barking muntjac startled us and every crackle, pop and snap of branches and leaves was sharpened in the quiet.

With my binoculars, I zoomed in on what I thought was a tiger print but it was just my imagination conjuring up an image because I was desperate to catch a glimpse of a tiger.

We climbed down and ploughed through swampish ground to retrieve more memory cards. Puangsone collected wild watercress, too, which we ate back at the camp along with freshly foraged wild raspberries. After three nights in stilt huts, the bamboo nests were a welcome change. High enough to be dangling, and to deter a prowling Indochinese tiger, I thought, as I climbed the little stepladder, and shuttered the “eyelid” of the pod cocooning myself inside. I lay there pondering the folktale about the malevolent tiger that was able to transform into a man to lure villagers to their death that Khamphew had just told us around the dying embers of the camp fire.

• The trip was provided by Audley Travel, which offers tailor-made holidays to Laos and has a 14-day trip covering Hanoi, Mai Chau, Vieng Xai, Nam Et-Phou Louey, Nong Khiaw and Luang Prabang. Prices start from £3,775 including return international flights, B&B accommodation, touring and transfers. The challenging five-day Cloud Forest Trek, including a night at the nests, costs from £404pp (when two travel). The easier two- or three-day trek to the salt lick and nests, covering around 12km at lower heights, costs from £135-£224pp (when two travel). Treks run in the dry season only, from October to June.