Limestone is used widely for the Angkor temples, and in most cases it is a cladding over the laterite stone core. There was no natural limestone in the Siem Reap area, so it had to be extracted from quarries near Kulen Mountain.
Quarrying the stone must have been a very tough job, using primitive materials. The photo shows modern workmen at a stone quarry near Beng Mealea using metal rods to cut the stone blocks. Tool marks on stones suggest this could have been similar to the method originally used.
The limestone plateau of Kulen, which extends for over twenty kilometres, is situated 30 kilometers from Angkor city. The logistics of transporting thousands of tonnes of stone would be a major project today, but in the 12th century it would have been an incredibly difficult undertaking, with tens of thousands of men and elephants working in hot humid conditions.
Looking at the narrow Siem Reap River today, it’s hard to imagine how these huge blocks could be moved along this waterway. But the river was significantly wider than it is today, as the ancient Khmers canalized this river by straightening it as part of the extensive irrigation system. This would enable the use of rafts to transport the stone.