Prosečne GPS koordinate za poštanski broj 409-840: 37.647, 125.708
Spisak gradova:
>> Yeonpyeong-myeon/연평면 409-840, Incheon/인천, Ongjin-gun/옹진군, GPS koordinate: 37.64731,125.70791
Spisak gradova:
>> Yeonpyeong-myeon/연평면 409-840, Incheon/인천, Ongjin-gun/옹진군, GPS koordinate: 37.64731,125.70791