Seongnam is affiliated with South Korea's Gyeonggi Province which locates in the middle part of Korean Peninsula. It's the central city of Gyeonggi Province. It's located on the south side of Gangdong-gu, Seoul. It's a highly developing new city of Seoul National Capital Area. It's the 8th largest city and the largest autonomous city.Shenyang officially established sister city relationship with Seongnam on August 31, 1998.Seongnam is the 10th sister city of Shenyang.