From the 9th to 15th century, the Khmer people ruled over a vast empire spanning modern Cambodia and Vietnam. In the center of their reign their build Angkor Watt, the city of temples, as a symbolic representation of the holy mountain Meru surrounded by the primordial ocean. Apart from a religious significance, the construction of channels and basins by the Khmer people had also a quite practical use. One of the largest basins, called in the local language baray, is almost 5 miles long and more than a mile wide and was used to collect rain during the Monsoon, as a water reserve for the dry season.
