This masonry wall, with an adorned entryway, also served as an aqueduct for the canal (details below), that transported water for the great city of Huari, Piquillakta, upper Urubamba valley, Cusco, Peru.
http://kyapa.tripod.com/agengineering/canaltechnology/canals.htm
Investigations further demonstrate that Cotocotuyoc was defensive in nature, and that it likely became a stronghold for the Wari as the valley occupation destabilized and finally collapsed. The use and abandonment of Cotocotuyoc may be associated with a shift in its water supply, a canal system linking the site to hillside springs
http://www.american.edu/anthro/andean/abstracts.cfm