30 January 2012 | By Alex von Tunzelmann, Lonely Planet Magazine

Caves were sacred to the Mayans, and locals say the Rio Frio Cave was a site of human sacrifices.

The jungle is cold at night. By the light of a crescent moon, we trek through pines and palms, pushing stray foliage aside, lifting our feet high over the treacherous knotted roots of strangler figs. The air smells of wet earth. It is still, and quiet, but we humans are not the only ones awake. A pair of eyes shines from the darkness, glimpses us, and is gone.

Through gaps in the trees above, the black sky looks like a jeweller's display, studded with millions of glittering stars. Ancient Mayans believed their sun god turned into a jaguar at dusk, and the constellations were his spots. Branches crack underfoot, but it is wise to tread carefully. Real jaguars roam these forests.

Through the gloom, the edges of a colossal pyramid rise up above the jungle canopy. It is one edge of a city, vanished for a millennium: Caracol, once the centre of a mighty Mayan empire.

More than 80 years ago, another adventurer came to these jungles, looking for lost cities, buried treasure and mystical ancient objects with strange powers. He was a dashing archaeologist between the two World Wars, instantly recognisable by his trademark hat. But his name was not Indiana Jones. It was FA Mitchell-Hedges.

George Lucas and Steven Spielberg have always denied that there was one specific inspiration for Indiana Jones, but Mitchell- Hedges - who gets name-checked in the fourth movie - is a well-qualified candidate. Like Indy, Mitchell-Hedges's version of a career in archaeology involved blowing things up, fighting villains and being callous to the scores of women who fell hopelessly in love with him.

We scramble through the mists up the side of one acropolis, clinging to the creepers and allspice trees that have overgrown it. What remains of the stairway belize on foot is slicked with moss and dew. It is easy to lose your footing, and tumble back down, bouncing off the steps like the sacrificial victims of a thousand years ago.

As the sky lightens to delicate shades of pale blue and tangerine, we reach the peak. A blood-curdling roar splits the silence. 'Have you seen Jurassic Park?' asks Calbert, our guide, a Mayan from a nearby village. 'Just kidding. That's a howler monkey.' A whole family of them, swinging through the trees on long black tails, babies clinging to the backs of adults. The noise is unbelievable: like something from the fires of hell. No wonder the Mayans worshipped howler monkey gods.

Just then, the sun glimmers over the horizon, and the ruined city is flooded with warm rose gold. This is the sight ancient priests awaited every morning: their god returning from his jaguar form, and illuminating the observatory with his blessing. The pink light picks out mysterious carvings in the stone, telling of ancient victories against the rival kingdom of Tikal, of captured slaves, of the blood sacrifice of a princess. But of the most mysterious artefact of all, there is no trace. For this is the kingdom of the crystal skull.

The legend of the crystal skull

Indiana Jones may have looked for crystal skulls in Peru, but he was way off track. The legend of the skulls comes from Belize, which is where Mitchell-Hedges came to look for mysteries back in 1926. Mitchell-Hedges claimed that he never sought fame, but this was not strictly true: he had his own radio show in New York, and wrote memoirs with titles such as Danger, My Ally and Battles With Giant Fish. He claimed to have fought with Pancho Villa in the Mexican Revolution, to have been asked by the British secret service to spy on Trotsky, and to have found the lost empire of Atlantis. Along the way, he stopped to hunt crocodiles, wrestle tiger sharks and engage in steamy romps with bar wenches. But his most famous feat was the discovery of the Skull of Doom, a lump of rock crystal fashioned into the shape of a human skull, glittering among the rubble in the ruined Mayan city of Lubaantun, Belize. Ancient priests, he said, could focus their energies through it, and will the death of their enemies. 'Several people who have cynically laughed at it have died,' he warned.

Even at risk of incurring death by Mayan curse, it is tempting to laugh cynically. The Skull of Doom was a fraud. It was almost certainly one of several that a dubious antiques dealer, Eugene Boban, secretly commissioned from German craftsmen in the 19th century. Boban sold a number of these skulls, on the pretence that they were of ancient Mayan or Aztec origin: one ended up in the Smithsonian Museum, Washington DC, and one in the British Museum. These days, both museums have their skulls labelled as fakes. Mitchell-Hedges, the old charlatan, did not find his skull at Lubaantun. He still had the receipt from when he bought it at Sotheby's.

How many of Mitchell-Hedges's adventures were real, and how many only existed in his imagination, is unknown. But he did come to Belize, hacking through jungles, meeting Mayan villagers and exploring deserted, tropical archipelagos, and he did excavate the ruins at Lubaantun. Clutching a dusty copy of his Belizean travelogue, Land of Wonder and Fear, I set out on the Hummingbird Highway to follow the route of his real-life adventure.

Meeting Captain Buck
Belize, formerly British Honduras, is a small country crammed with diversity. Ecosystems range from mountainous pine forests to reefs, savannahs to jungles. These support a plethora of flora and fauna, including 540 species of bird and 124 species of mammal. The human population is diverse too. Mayan teenagers in hoodies shop in the Ah Fang Taiwanese supermarket. Bearded Amish and Mennonite men drive their horse-carts past the Bismilla Lebanese caf�. South Asian youths play pool in a roadside shack. Creoles and Canadians dance the night away to Garifuna music, the unique blend of African and Amerindian cultures created when, in 1635, escaped African slaves from a Spanish ship allied with the native Caribs on St Vincent, and later spread to Belize. Even in remote villages, most people will happily chat away to you in perfect English. Belize is the only Anglophone country in Central America, making it easy and pleasurable to explore, and to meet new friends along the way.

It is not long before we reach the colourful seaside town of Dangriga. My plan, scribbled on a scrap of paper, sounds more like Moby-Dick than Raiders of the Lost Ark: I should go to the Riverside Caf� and look for one Captain Buck. No disappointment is in store for, aside from having both legs and being Creole, Captain Buck looks the part of Captain Ahab. He is a grizzled old seadog in a booth near the bar, tucking into the local delicacy of crispy pastries - known as fry jack, and served with everything. The Captain isn't much of a talker. He nods towards his motorboat, moored just outside.

It is a searingly bright Caribbean day, and the sea glitters as if filled with sequins. Ten minutes out of the harbour, a shiny grey fin breaks the surface. Captain Buck veers the boat over towards it. For a fleeting second, four or five bottlenose dolphins curve out of the surf by the bow, before plunging back into the depths.

Buck fires the motor again to Man-O'- War Caye, a tiny island that seems from the distance to have some sort of pestilence buzzing above it. But the specks in the air are not flies. They are hundreds of magnificent frigatebirds, swooping and gliding over their nesting spot. Captain Buck takes the boat so close that we are enveloped in their flock: the males puffing up scarlet throats, the females circling the trees. An inquisitive pelican paddles up to the boat to see if we have fish to spare.

Past Man-O'-War Caye, we cross a mangrove lagoon enclosed between two sandy crescents. It is filled with manatees, giant sea mammals that were supposedly mistaken for mermaids by the sailors of yore. The manatee is a noble beast but, with its sunken eyes, bloated cigar-shaped body and lumpy face, it is not the prettiest. Those sailors had not seen a woman for a very long time. Finally, we reach Tobacco Caye, the same tiny sandstrip where Mitchell-Hedges broke his journey south from Belize City to Punta Gorda. These days, it is home to a cluster of cabanas for snorkelers, divers and kayakers.

Belize is famous for its dive sites, particularly the Great Blue Hole - a perfectly circular sinkhole, as wide as the Eiffel Tower is tall, set in the middle of Lighthouse Reef. Plunging to 120 metres, the hole is a favourite lurking ground of sharks, and was made famous by Jacques Cousteau. Even for the casual snorkeler, there are plenty of thrills to be had, and Tobacco Caye is an ideal spot to start having them: the reef starts just a few yards offshore. If you can persuade Captain Buck to take you out to a channel, you can jump in amid eagle rays, turtles, tarpon, barracudas and even whale sharks.

The temptation of the exotic
Mitchell-Hedges was more into battling giant fish than appreciating them, and he spent his time on Tobacco Caye alternately big-game fishing and scouring the islands for Mayan ruins. He found lots of fish, but no Mayans. As the sun begins to dip and the sky fades from azure to violet, my inquiries about crystal skulls don't get very far either. Kirk, the barman at Tobacco Caye Lodge, looks confused: 'Crystal who?' I explain. He gives me a pitying look and a pi�a colada.

The pi�a colada - rum, coconut milk, and fresh pineapple - brings to mind a very different aspect of Mitchell-Hedges's adventures. Once, he claimed to have been presented with exotic fruit by an admiring tribe of female Amerindians, who hoped he might be the answer to their acute shortage of husbands. Manfully, he resisted, with the immortal words: 'Personally, I refuse to be seduced by pineapples.' If pineapples test your fortitude, you could be in trouble. Pi�a coladas made fresh on the beach, with authentic Belizean fruit, are shamefully seductive at the end of a hot Caribbean day.

Back on the mainland, we head south, through the eerie primeval swamps of the Cockscomb Basin. Trekking along muddy jungle paths, we follow a trail of fresh jaguar paw prints. The cat does not want to be found. Instead, it leads us to a ghostly sight: the rusting chassis of a high-wing aircraft, crashed into the trees many years ago by some zoologists. They survived, but left the wreck to be eaten up by the jungle.

Few tourists make it further south than Placencia, a glitzy peninsula inhabited by Belize's celebrities, but that is a huge mistake. Southern Belize's little-known Toledo district is outstandingly beautiful, and a true wilderness: 1,700 square miles, 26,000 people and only three petrol stations. No big resorts befoul the coastline, and the only airport is a landing strip, accepting nothing much larger than a 16-seater plane. With a local expert, such as guide Bruno Kuppinger, you can have a true travel adventure.

After a few years playing the stock market in New York, Mitchell-Hedges complained that he had been 'sidetracked into a counterfeit jungle of counterfeit excitement when I should have been rollicking down the trail of adventure in the primitive, unspoiled wilds'. Similarly, Bruno was a successful businessman in Germany before he got fed up with the rat race, and moved to Belize to live in a tent.

But there the similarity between the two men ends, for Bruno is an unassuming man of extensive cultural knowledge and unimpeachable honesty. 'Oh, ja, the famous crystal skull,' he says, eyeing me nervously to check my sanity. 'It's not mentioned in the excavation reports. But I can take you to meet someone who knows all about it.'

Alien intervention?
Daryl Capps lives in the pretty seaside town of Punta Gorda. This white-haired, congenial American was a member of the Society of the Crystal Skulls, founded in 1945 in California to investigate the paranormal and archaeological claims made for these objects. Daryl has chosen to make his home here, just 26 miles from Lubaantun - but he doesn't believe the Skull of Doom is genuine. 'It's too perfect,' he says, with a laugh.

'Some people think crystal skulls are of alien origin,' he continues, pointing to a photograph taken through the Skull of Doom, which appears to show a shadow of a 1950s-style flying saucer through the middle of it. 'But look at the uncropped photo.' In the full version, the origin of the flying saucer is revealed: it's a 1950s-style ceiling fan, refracted through the skull.

Sceptic though he may be, Daryl does believe that several of the other crystal skulls purportedly discovered all over the Americas are authentic - and raises the question of whether they may emit mysterious psychometric energies. The British Museum is circumspect, pointing out that no crystal skull has ever been found at a well-documented, official excavation. As for me, I couldn't say it better than Indiana Jones: 'I don't believe in magic, a lot of superstitious hocuspocus. I'm going after a find of incredible historical significance.' Lubaantun itself is that find, and it's within a few hours' reach, up the river and through thick forests.

From Punta Gorda, Mitchell-Hedges took canoes up the Rio Grande (not to be confused with the river of the same name that's part of the US-Mexico border). Now, the journey is made by motorboat. As saltwater turns to freshwater, the mangroves are replaced by huge cohune palms, their quills of green leaves held high in the warm air, and by sturdy cotton trees, with pale, gnarled roots stretching down to the shore. Creepers trail into the crocodile-infested river. In a feathery thicket of bamboo, gigantic orange and grey iguanas hang heavy, like living Christmas decorations. Three Mayan children crawl on their bellies along an overhanging trunk, hoping to catch one of these monsters for dinner.

Around Lubaantun, most of the Mayan population lives in villages of pimento sticks and palm thatch. When we arrive, the women come to greet us, wearing puffsleeved dresses in shades of flax, grape and lime. The Mayans here stood firm against imperial rule until the 17th century. Neither army nor church could conquer them: they were finished off by European diseases. The current population migrated from Guatemala a century ago, and has re-established a traditional way of life.

The city's mysteries
Lubaantun is neither the largest nor the most elaborate of pre-conquest Mayan sites, but it is one of the most atmospheric. After you have navigated dirt tracks in an all-terrain vehicle, you scramble down a perilous grassy slope cut into the trees, cross a bridge, then climb a hillside to a high plateau. It is late afternoon when we reach the edge of the city: piles of sandstone slabs, heaped higgledy-piggledy, amid dense palms and swirls of mist.

These stones were cut so precisely that they once fitted together without cement. Now, they lie scattered around, like building blocks in a messy child's room. The reason is not just the passage of centuries. Mitchell-Hedges's partner in crime, Thomas Gann, 'excavated' this city using dynamite.

By blasting huge holes in the sides of ancient monuments, he hoped to find tombs filled with gold. But Gann, like the conquistador Hern�n Cort�s before him, found no gold in the Mayan lands. Mayans didn't value the stuff; their most prized substance was jade. And, like Cort�s, Gann caused irreparable damage in his obsessive pursuit of riches.

The good news is that the ruined ruins at Lubaantun comprise a tiny part of the entire site. 'Ninety per cent of Lubaantun has never been excavated,' Bruno tells me. So there are mysteries still lying here, undiscovered? 'Oh ja, all around these hills.' Maybe a crystal skull? 'No, I don't think so.' Bruno does not want anyone turning up with a case of dynamite, but there is a better option. 'We are hoping to start archaeology tours at Uxbenka, southwest of Lubaantun. Visitors will be able to dig on the ruins, but it will all be done under proper academic supervision.'

As it sinks down into the mists, the sun turns blood orange. The city is quiet, except for the chirping of cicadas. A millennium ago, priests and nobles in feathered headdresses strode the avenues. Merchants traded obsidian in the busy markets. Young men played for cheering crowds in the ballcourts. Now, it has all been swallowed up by the jungle, many of its secrets lost forever. 'In the setting sun the immensity of the ruins we had uncovered came home to us with overwhelming force,' wrote Mitchell-Hedges at this very spot. 'Slowly the sky crimsoned, a red glow tinged the jungle and the desolate courtyards, the terraces, the pyramids of this great city which we had called Lubaantun - the Maya word for "The City of Fallen Stones."'

And the crystal skull? Lubaantun is full of mysteries, but that isn't one of them. The Old Belize Bar in Belize City has a plastic copy you can have your photograph taken with. It's only slightly less authentic than the Skull of Doom. Should you wish to be seduced by pineapples, they'll even serve you another pi�a colada while you, like Mitchell-Hedges, watch the sun set over the horizon. Unlike him, you won't need to invent your adventures.