administrative divisions of south korea ansan anseong area bucheon busan cheonan dongducheon gapyeong county geographic coordinate system geography of south korea geumjeong station gimpo goyang gunpo station guri gwacheon gwangmyeong gyeongbu line gyeonggi-do hanam hangul hanja icheon namyangju osan paju pocheon population population density pyeongtaek seongnam seoul seoul national capital area siheung south korea suwon uijeongbu uiwang yangju yeoncheon county yongin