▁after ▁ 2 7 0 0 ▁years ▁still ▁provides ▁drink ing ▁and ▁agricult ural ▁water ▁to ▁nearly ▁ 4 0 , 0 0 0 ▁people . ▁ ▁Its ▁main ▁well ▁is ▁more ▁than ▁ 3 6 0 ▁meters ▁deep ▁and ▁the ▁q an at ▁is ▁ 4 5 ▁kilom eters ▁long . ▁Y az d , ▁K hor as an ▁and ▁K erman ▁are ▁the ▁known ▁zones ▁for ▁their ▁dependence ▁with ▁an ▁extensive ▁system ▁of ▁q an ats . ▁ ▁In ▁traditional ▁Pers ian ▁architecture , ▁a ▁Kar iz ▁( ک ا ر ی ز ) ▁is ▁a ▁small ▁Q an at , ▁usually ▁within ▁a ▁network ▁inside ▁an ▁urban ▁setting . ▁Kar iz ▁is ▁what ▁dist ributes ▁the ▁Q an at ▁into ▁its ▁final ▁destin ations . ▁ ▁Kar iz ▁in ▁Pers ia ▁Q an ats ▁of ▁Gon abad ▁also ▁is ▁called ▁ ▁kar iz ▁K ai ▁Kh os row ▁is ▁one ▁of ▁the ▁oldest ▁and ▁largest ▁q an ats ▁in ▁the ▁world ▁built ▁between ▁ 7 0 0 ▁BC ▁to ▁ 5 0 0 ▁BC . ▁It ▁is ▁located ▁at ▁Gon abad , ▁Raz avi ▁K hor as an ▁Province , ▁Iran . ▁This ▁property ▁contains ▁ 4 2 7 ▁water ▁well s ▁with ▁total ▁length ▁of ▁ 3 3 1 1 3 ▁meters . ▁This ▁site ▁were ▁first ▁added ▁to ▁the ▁UN ES CO ' s ▁list ▁of ▁tent ative ▁World ▁Heritage ▁S ites ▁in ▁ 2 0 0 7 , ▁then ▁officially ▁ins cribed ▁in ▁ 2 0 1