linguistic:paraphrasing, structural:summarization
Cheonan is the largest and most densely populated city of Chungcheongnam-do, South Korea, and the third largest city in the Hoseo region after Daejeon and Cheongju. Cheonan borders Gyeonggi-do in the north, Chungcheongbuk-do to the east and southeast, Sejong City to the south and Asan-si and Gongju-si to the west and southwest. Cheonan has been called "the core city of [the] nation" due to its location 83.6 km (51.9 mi) south of the national capital, Seoul, in the northeast corner of South Chungcheong, serving as a transportation hub to the Seoul Capital Area and surrounding regions. Cheonan is connected to various freeways and railways including the National Highways 1 and 21, the Expressways 1-Gyeongbu and 25-Honam, and the city's Korail station serves the Gyeongbu Line and the Janghang Line, with services of the KTX. Cheonan is one of the furthest places from Seoul connected to the Seoul Subway Line 1.