The prop­er­ty includes five aflaj irri­ga­tion sys­tems and is rep­re­sen­ta­tive of some 3,000 such sys­tems still in use in Oman. The ori­gins of this sys­tem of irri­ga­tion may date back to AD 500, but archae­o­log­i­cal evi­dence sug­gests that irri­ga­tion sys­tems exist­ed in this extreme­ly arid area as ear­ly as 2500 BC. Using grav­i­ty, water is chan­nelled from under­ground sources or springs to sup­port agri­cul­ture and domes­tic use. The fair and effec­tive man­age­ment and shar­ing of water in vil­lages and towns is still under­pinned by mutu­al depen­dence and com­mu­nal val­ues and guid­ed by astro­nom­i­cal obser­va­tions. Numer­ous watch­tow­ers built to defend the water sys­tems form part of the site reflect­ing the his­toric depen­dence of com­mu­ni­ties on the aflaj sys­tem. Threat­ened by falling lev­el of the under­ground water table, the aflaj rep­re­sent an excep­tion­al­ly well-pre­served form of land use.