▁North west ▁China . ▁The ▁pre fect ure - level ▁city , ▁located ▁on ▁the ▁banks ▁of ▁the ▁Y ellow ▁River , ▁is ▁a ▁key ▁regional ▁transport ation ▁hub , ▁connecting ▁areas ▁further ▁west ▁by ▁rail ▁to ▁the ▁eastern ▁half ▁of ▁the ▁country . ▁Histor ically , ▁it ▁has ▁been ▁a ▁major ▁link ▁on ▁the ▁Northern ▁Sil k ▁Road ▁and ▁it ▁stands ▁to ▁become ▁a ▁major ▁hub ▁on ▁the ▁New ▁E uras ian ▁Land ▁Bridge . ▁The ▁city ▁is ▁also ▁a ▁center ▁for ▁heavy ▁industry ▁and ▁pet ro chem ical ▁industry . ▁ ▁L anz hou ▁is ▁home ▁to ▁ 3 , 6 1 6 , 1 6 3 ▁inhabitants ▁at ▁the ▁ 2 0 1 0 ▁census ▁and ▁ 2 , 1 7 7 , 1 3 0 ▁in ▁the ▁built - up ▁area ▁( urban ) ▁of ▁. ▁By ▁ 2 0 1 8 , ▁its ▁population ▁within ▁the ▁central ▁urban ▁area ▁of ▁ ▁rose ▁to ▁ 2 , 8 9 0 , 0 0 0 ▁people . ▁ ▁History ▁ ▁Origin ally ▁in ▁the ▁territory ▁of ▁the ▁Western ▁Q i ang ▁pe op les , ▁L anz hou ▁became ▁part ▁of ▁the ▁territory ▁of ▁the ▁State ▁of ▁Q in ▁in ▁the ▁ 6 th ▁century ▁BC . ▁ ▁In ▁ 8 1 ▁BC , ▁under ▁the ▁Han ▁dynast y ▁( 2 0 6 ▁BC – AD ▁ 2 2 0 ), ▁it ▁was ▁taken ▁from ▁the ▁H uns ' ▁Hu and i ▁Ch any u ▁and ▁made ▁the ▁seat ▁of