▁BC . ▁In ▁ 1 9 8 6 , ▁seven ▁ancient ▁Chinese ▁maps ▁were ▁found ▁in ▁an ▁ar che ological ▁exc av ation ▁of ▁a ▁Q in ▁State ▁tomb ▁in ▁what ▁is ▁now ▁F ang mat an , ▁in ▁the ▁vic inity ▁of ▁T ians hui ▁City , ▁G ans u ▁province . ▁Before ▁this ▁find , ▁the ▁earliest ▁ext ant ▁maps ▁that ▁were ▁known ▁came ▁from ▁the ▁M aw ang du i ▁Han ▁tomb ▁exc av ation ▁in ▁ 1 9 7 3 , ▁which ▁found ▁three ▁maps ▁on ▁sil k ▁dated ▁to ▁the ▁ 2 nd ▁century ▁BC ▁in ▁the ▁early ▁Han ▁D ynast y . ▁The ▁ 4 th - century ▁BC ▁maps ▁from ▁the ▁State ▁of ▁Q in ▁were ▁drawn ▁with ▁black ▁in k ▁on ▁wooden ▁blocks . ▁These ▁blocks ▁fort un ately ▁surv ived ▁in ▁so aking ▁conditions ▁due ▁to ▁under ground ▁water ▁that ▁had ▁se ep ed ▁into ▁the ▁tomb ; ▁the ▁quality ▁of ▁the ▁wood ▁had ▁much ▁to ▁do ▁with ▁their ▁surv ival . ▁After ▁two ▁years ▁of ▁slow - d ry ing ▁techniques , ▁the ▁maps ▁were ▁fully ▁restored . ▁ ▁The ▁territory ▁shown ▁in ▁the ▁seven ▁Q in ▁maps ▁overlap ▁each ▁other . ▁The ▁maps ▁display ▁trib ut ary ▁river ▁systems ▁of ▁the ▁J ial ing ▁River ▁in ▁S ich uan ▁province , ▁in ▁a ▁total ▁measured ▁area ▁of ▁ 1 0 7 ▁by ▁ 6 8   km . ▁The ▁maps ▁featured ▁rect angular ▁symbols ▁enc asing ▁character ▁names ▁for ▁the ▁locations ▁of