Archaeologists studying Cambodia's Angkor Wat say a series of canals may have been used as a shortcut to bring 5 million tons of stones to the temple site.

The sandstone blocks used to build the world's largest Hindu temple complex, each weighing up to 1.5 tons and originating from quarries at Mount Kulen, had long been thought to have been taken 25 miles along a canal to Tonl Sap Lake, rafted another 20 miles across the lake, then taken up the Siem Reap River for 10 miles against the current.

However, Etsuo Uchida and Ichita Shimoda of Waseda University in Tokyo, using satellite images, say they've identified other ancient canals that could have been a shortcut for the 12th-century construction project, NewScientist.com reported.

The canals led from the foot of Mount Kulen directly to Angkor, a gentle 20-mile route as opposed to the arduous 55-mile trek previously suggested, the researchers said.

Uchida and Shimoda also uncovered more than 50 quarries at the foot of Mount Kulen and along the route containing stones that matched those in the temples.

Uchida said he believed all the stone used for the Angkor Wat monuments was probably transported along these canals.

Uchida's theory could be confirmed by searching for blocks that fell overboard into the canals, a U.S. researcher suggests.

Mitch Hendrickson of the University of Illinois said he believes the canals were used for a number of purposes, including the transportation of important minerals such as iron.