A cry rang out through the jungle night, piercing even through the shattering roars of the howler monkeys. It sounded like a cry for help. A human voice yelling out in fear or agony. “Es el señor de la selva,” came the quiet explanation of my guide. The Lacandon rainforest, in Mexico’s southernmost Chiapas region, is a mysterious place. And ‘the lord of the jungle’ was just another of the unfathomable mysteries that the Lacandon people seem to live with on a daily basis. “It is not a man. Nor an animal,” Lukas continued, his faces shrouded in his long hair and shadowed by the flickering light of our dying campfire. “It is a spirit. It is calling for help to trick us. Anyone who mistakes it for a human and goes to try to help will be killed and eaten.”

I nodded and shrugged. Just another one of the things I was destined not to completely understand about the Lacandon and this remote jungle haven that they have called home for more than five hundred years. The Lacandon are the most direct descendents of the Mayan ‘refugees’ who fled south after the arrival of the Spanish. Other groups continued fleeing to Guatemala and Honduras where they were finally absorbed into other cultures (principally that of the all-conquering tide of Spanish). But the Lacandon turned aside in Chiapas to melt into the great expanse of rainforest along the Usumacinta River (biggest river in Central America). And there they stayed – to all intents and purposes forgotten – for the best part of four hundred years.

There are now said to be less than seven hundred pure-blooded Lacandon left. They are a people literally on the verge of extinction. They must marry outside the group to avoid inbreeding yet with every young Lacandon who leaves there is another step towards extinction. With them will disappear their last of the pure Mayan religion, their jungle medicine and survival expertise, and the last of the pure Mayan language.

When I hired Lukas to guide us here I convinced him to also bring along his ten year-old son Juan. I wanted Juan to see some of the jungle and to listen to the stories I was going to ask his father about the history and beliefs of the Lacandon people. I was impressed to see though that, even at this tender age, Juan would be more than capable of surviving alone in the jungle should he ever have to. We carried food for several days and a live hen that we could kill when the need for fresh meat became too much. Juan would dive for snails that he could use as bait and within an hour the pair had caught twenty tasty fish.

We were now camped on an island in Lagunas de Lacanjá. The island was about ten metres across and sometime – way back in pre-Colombian history, in a time even forgotten to the Lacandones – the entire island had been turned into a pyramid. The flat top where we now camped was once an important ceremonial spot. I had long ago been reclaimed by the jungle but it is still used by the Lacandon as a sacred place for worship and blessings.

The trek to the island turned out to be a challenging one: there were mosquitoes of a size I have only seen once before (on the Mekong); there were spiked plants that pricked your fingers should you grab for a handhold (a week later my fingers are still slowly festering from their poison); lethal scorpions and coral snakes lay on our path; we saw the spoor of a big jaguar; there is malaria and a particularly virulent strain of dengue. When you reach the lagunas themselves you find that they are surrounded by a barely impenetrable wall of elephant grass, which barely covers the acres of quicksand – actually black, liquid mud – which can swallow a man in a matter of seconds.

Nobody in his right mind would attempt all this without a good local guide. But Lukas led us undaunted through all these obstacles and we found his canoe, half sunk in the grasses at the edge of the lake. We watched while Juan repaired the holes with clay and then loaded our packs into the boat. It was not big enough to take us all so I volunteered to swim the two hundred metres to the island.

It was only when we were nearing the banks that Lukas bothered to mention the last – and most fearful – of all the guardians of the sacred lakes. The lake is also home to five metre alligators. According to him it is entirely safe in the daytime though and the alligators would only attack a swimmer at night-time…a story that, to me, seemed about as logical as that of the ‘señor de la selva.’