Gosancheon-ro, Gosan-myeon, Wanju-gun postal codes (238)
On Gosancheon-ro in Gosan-myeon, Wanju-gun the postal code depends on the building number: numbers 158-1–475 use 55307, numbers 485-7–556 use 55308, numbers 567-14–654 use 55311, and 1 more ranges. Data as of August 2026.