▁on ▁September ▁ 1 0 , ▁ 1 9 7 6 . ▁ ▁The ▁art ▁installation ▁was ▁first ▁conce ived ▁in ▁ 1 9 7 2 , ▁but ▁the ▁actual ▁project ▁took ▁more ▁than ▁four ▁years ▁to ▁plan ▁and ▁build . ▁After ▁it ▁was ▁installed , ▁the ▁build ers ▁removed ▁it ▁ 1 4 ▁days ▁later , ▁leaving ▁no ▁visible ▁trace ▁behind . ▁ ▁The ▁Install ation ▁ ▁The ▁art ▁installation ▁consisted ▁of ▁a ▁ve iled ▁f ence ▁ ▁long ▁extending ▁across ▁the ▁hills ▁of ▁Son oma ▁and ▁Mar in ▁count ies ▁in ▁northern ▁California , ▁United ▁States . ▁ ▁The ▁ ▁high ▁f ence ▁was ▁made ▁of ▁ 2 0 0 , 0 0 0 ▁square ▁meters ▁( 2 , 2 2 2 , 2 2 2 ▁square ▁feet ) ▁of ▁heavy ▁w oven ▁white ▁n yl on ▁fabric , ▁which ▁created ▁ 2 , 0 5 0 ▁pan els , ▁and ▁was ▁hung ▁from ▁steel ▁c ables ▁by ▁means ▁of ▁ 3 5 0 , 0 0 0 ▁hook s . ▁ ▁The ▁c ables ▁were ▁supported ▁by ▁ 2 , 0 5 0 ▁steel ▁pol es ▁( each : ▁ 6 . 4 ▁meters ▁/ ▁ 2 1 ▁feet ▁long ▁or ▁ 9 ▁cent im eters ▁/ ▁ 3 . 5 ▁inches ▁in ▁diameter ) ▁embedded ▁ 1 ▁meter ▁( 3 ▁feet ) ▁into ▁the ▁ground , ▁b rac ed ▁by ▁steel ▁gu y ▁w ires ▁( 1 4 5 ▁kilom eters ▁/ ▁ 9 0 ▁miles ▁of ▁steel ▁cable