In addition to their sophisticated roads, the ancient Khmer also built a network of irrigation channels, causeways and reservoirs, many of which remain in use today.
The vast Western Baray was the largest of all. This immense reservoir, measuring 8.5 by 2.25 kilometres, was contained within earthen banks and filled solely by rainwater. Although built 800 years ago, it still contains most of its water. The small temple at the centre can be reached by boat from a small resort accessed by a road three kilometres west of the Siem Reap airport. The best view of the Baray is from either Phnom Bakheng or the Angkor balloon, which flies daily two kilometres west of Angkor Wat.
The slightly smaller East Baray extends 7.5 by 1.75 kilometres, but it dried up centuries ago. At its centre lies the splendid brick East Mebon temple, with five towers in a three-tiered pyramid representing the mythical Mount Meru.
The dried-up reservoir is now a rich farmland area centred on the village of Pre Dak. The villagers exploit the tourist trade by selling souvenirs and basketwork at almost all roadside houses. Travellers from Pre Dak to Banteay Srey temple can see the line of trees and the northern earth bank of the old reservoir one kilometre north of Pre Dak village.