Archaeologists have long wondered how 12th-century builders transported the massive sandstone blocks—at least five million of them—that make up Angkorian temples in Cambodia. Researchers identified a probable source at Mount Kulen and surmised that barges brought the stone by way of canals to Tonle Sap Lake and then, against the current, up the Siem Reap River—a route some 55 miles long.
Recently, however, Google Earth satellite images gave researchers from Waseda University in Japan reason to conduct a more thorough field study. They identified another, more direct route from Mount Kulen, only 21 miles via waterways. “We found the transportation road and canals about two years ago on the satellite images, and then conducted the field investigation,” says Estuo Uchida, a coauthor of the study.
Since then, the Waseda team has uncovered more than 50 quarries, the source of what they expect to be 70 percent of all the stone used in the Angkorian period. But they remain unsure which quarry was the source for the most famous temple, Angkor Wat, built to honor the Hindu god Vishnu and later converted to a Buddhist temple. “We continue field investigations to find the rest of the quarries,” Uchida says.
Because of the heat, humidity, and dense forest, the Japanese team can dig only in December and January. They are matching the chemical composition of the stone in the quarries to the gray to yellowish brown blocks in the monuments and determining their age by using magnetic susceptibility.