Via NewScientist:
Looks like the builders of Angkor Wat may have taken a short cut transporting the materials used in the construction of the temple. Newly-discovered traces of a series of long-gone canals may have halved the distance it took to transport massive blocks of sandstone from quarries at Mount Kulen.
The sandstone blocks each weigh up to 1.5 tonnes and originate from quarries at Mount Kulen. It was thought they were taken 35 kilometres along a canal to Tonlé Sap Lake, rafted another 35 km along the lake, then taken up the Siem Reap River for 15 km, against the current.
Thinking this was unlikely, Etsuo Uchida and Ichita Shimoda of Waseda University in Tokyo, Japan, used satellite images to search for a shortcut. The canals they discovered led from the foot of Mount Kulen to Angkor – a gentle 34-km route, as opposed to the arduous 90-km trek previously suggested.



