In 1860 the French naturalist Henri Mouhot came upon an enchanting temple buried in the jungle of western Cambodia. It thrust spires of finely carved sandstone into the sky, and its open galleries held an artistic treasure: more than a mile of delicate bas-relief stone panels. "It is grander than anything left us by Greece and Rome," wrote Mouhot in his diary.
The temple, called Angkor Wat, was the work of the ancient Khmer kings of Angkor, whose empire stretched from what is now southern Vietnam to Burma. Today a first-time visitor may feel like a modern Indiana Jones who spies misty towers peaking behind dense foliage and thinks he has discovered a lost civilization.
In many ways it is. Angkor Wat, a Hindu shrine dedicated to the god Vishnu, is one of hundreds of stone structures built a thousand years ago over a 200- sq.-mi. area. Although largely abandoned for five centuries, more than 270 of the temples have survived intact. But little is known about the society that created one of the architectural wonders of the world.
( The question now is whether this wonder will be lost again. The temples of Angkor are deteriorating steadily as they slowly drown in a giant swamp. While preservation efforts have focused on the facades, the foundations have been eroding. New restoration proposals by countries from Japan to Poland have raised hopes that the temples will be saved, but progress is hampered by a lack of coordinated planning and by corruption in Cambodia.
To prevent further deterioration of the Angkor monuments, scientists need to explore what made the ancient society work. At a minimum, they have to understand the remarkable water-management system created by the Khmers. Beginning in the late 9th century a succession of Kings constructed enormous reservoirs, some as large as 20 sq. mi. These barays and a complex gravity-fed network of moats and canals provided an almost continuous supply of water so that three rice crops a year could be grown. That production enabled Khmer Kings to extend their empires and build temples to their own divinity. It is the destruction of that intricate water system that could drown most of the major monuments.
The most recent threat to Angkor arose during Cambodia's 20-year-long civil war, which began in the early 1970s. The Khmer Rouge, whose genocidal reign of terror killed an estimated 1 million Cambodians, did little direct damage to the monuments, but the fighting made maintenance impossible. Says B. Narasimhaiah, the head of an Indian archaeology team at Angkor Wat: "Wherever there is a small crack, dust will accumulate and soon a bush will spring up." All but a few of the major temples are covered in weeds, small bushes and even large trees.
Less obvious, but more insidious, is the water damage, according to archaeologist Richard Engelhardt, the director of UNESCO operations in Cambodia. The water system was neglected for centuries, and it totally collapsed following the construction of grandiose hydroprojects by the Khmer Rouge. They dammed the Siem Reap River, an integral part of the ancient system, in order to create their own baray farther north. As a result, the moats and canals surrounding the temples of Angkor turned into swamps.