Cambodia\'s busy temples Even before the first blush of sunlight has touched the jungle, I catch sight of the faces through the darkness. Crafted from great blocks of stone, mottled with lichen, weatherworn by centuries of tropical rain, they leer out towards the last strains of night. With each minute that passes more are revealed, as if their numbers are swelling, from a handful until there is a vast stone army of heads.
The jungle is stirring around me, the vines and dense undergrowth alive with all manner of life - macaques leap from one branch to the next, dragonflies pause on dew-covered leaves, and multi-coloured birds dart and swoop through the canopy. As the darkness melts away into light I make out the twisted roots of silkwood trees, curving through the ruins, a realm right out of Indiana Jones.
In a world abundant with possibility for the intrepid traveller, no destination is quite as bewitching as Angkor, the ruined capital of ancient Cambodia. The first time I visited, 15 years ago, the area was still heavily mined, a legacy of the devastating reign of terror at the hands of the Khmer Rouge. Back then I had to examine the temples, monasteries, and fortified bastions from a distance. Venturing beyond the scarlet skull and cross bones signs - which peppered the undergrowth - would have put me at risk of losing my feet.
But time is healing Cambodia and, at last, Angkor - a Unesco World Heritage Site - is safe once more. Yet, despite its extraordinary size and significance, the ancient capital of the Khmer empire tends to be overlooked by visitors from outside the region.
A vast series of temples, statues, and religious buildings, spread over an area the size of Manhattan, Angkor was the most populated ancient centre of the pre-industrial age. Thought to have had a million inhabitants at its height 1,000 years ago (compared with London\'s 30,000 at the time), it was laid out on a jaw-dropping scale.
At the centre of it all, encircled by a moat as wide as two football fields, is Angkor Wat, its name meaning \"Temple of the Capital\". Regarded as the largest religious structure ever completed, it stands as tall as Notre Dame Cathedral, which was completed at about the same time. The cornerstone of a mighty civilization that rose, and eventually waned, it was subsumed into the surrounding jungle. And there it lay for generations, until rediscovered by the West a century and a half ago.
The French philologist Henri Mouhot was one of the first Europeans to set eyes on the ruins, back in 1860. But he didn\'t actually discover Angkor, because the ancient Khmer capital was never really \"lost\". The local tribesmen knew very well that the jungle was packed with ruins. Abandoning it all, they preferred to live on the margins of the nearby Tonlé Sap Lake rather than in the interior.
And it was the lake that, curiously, gave rise to the entire Khmer culture in the first place. But the story of how Angkor came to be begins far away - in Tibet, where the melted snows of the Himalayas flow down the great snaking length of the Mekong. Eventually reaching the shallow delta, the waters feed into the South China Sea. But at the height of the seasonal floods, the current stops and the waters back up, essentially reversing the Mekong\'s flow. In one of nature\'s most peculiar phenomena, the river flows in the opposite direction for four months each year, with the overflow pooling into the Tonlé Sap Lake.
With the waters surging through the surrounding forests, the lake quadruples in size, becoming an inland sea - 160 kilometres long and half as wide. Teaming with fish, more than in any other body of fresh water on earth, Tonlé Sap becomes an angler\'s dream. And then, as the flood waters recede, the mud plains provide the perfect conditions for cultivating rice. The abundance of fish and rice were, for the ancient Khmer, the foundation stones of an empire. As the Nile gave birth to ancient Egypt, so the reversing Mekong spawned the culture that had at the centre of its capital the magnificent Angkor Wat.