▁This ▁precision , ▁combined ▁with ▁the ▁rounded ▁corners ▁of ▁the ▁blocks , ▁the ▁variety ▁of ▁their ▁inter lock ing ▁shapes , ▁and ▁the ▁way ▁the ▁walls ▁lean ▁in ward , ▁is ▁thought ▁to ▁have ▁helped ▁the ▁ru ins ▁surv ive ▁dev ast ating ▁earth qu akes ▁in ▁C uz co . ▁The ▁longest ▁of ▁the ▁three ▁walls ▁is ▁about ▁ 4 0 0   met ers . ▁They ▁are ▁about ▁ 6   met ers ▁tall . ▁The ▁estimated ▁volume ▁of ▁stone ▁is ▁over ▁ 6 , 0 0 0   c ub ic ▁meters . ▁Est im ates ▁for ▁the ▁weight ▁of ▁the ▁largest ▁and es ite ▁block ▁vary ▁from ▁ 1 2 8   ton nes ▁to ▁almost ▁ 2 0 0   ton nes . ▁ ▁Following ▁the ▁sie ge ▁of ▁C us co , ▁the ▁Sp ani ards ▁began ▁to ▁use ▁Sac say hu am án ▁as ▁a ▁source ▁of ▁stones ▁for ▁building ▁Spanish ▁C uz co ; ▁within ▁a ▁few ▁years , ▁they ▁had ▁taken ▁apart ▁and ▁demol ished ▁much ▁of ▁the ▁complex . ▁The ▁site ▁was ▁destroyed ▁block ▁by ▁block ▁to ▁build ▁the ▁new ▁Spanish ▁government al ▁and ▁religious ▁buildings ▁of ▁the ▁colonial ▁city , ▁as ▁well ▁as ▁the ▁houses ▁of ▁the ▁wealth iest ▁Sp ani ards . ▁In ▁the ▁words ▁of ▁Gar cil aso ▁de ▁la ▁V ega ▁( 1 9 6 6 : 4 7 1 ▁[ 1 6 0 9 : ▁Part ▁ 1 , ▁Book . ▁B k . ▁ 7 , ▁Ch