The Geomdeok Mine , located in Geumgol - dong , Dancheon - si , Hamgyeongnam - do , has been in operation since 1932 .
Is the largest zinc mine in East Asia .
The Geomdeok Mine , located in Geumgol - dong , Dancheon - si , Hamgyeongnam - do , has been in operation since 1932 and is the largest zinc mine in East Asia .