Metro, Seoul, South Korea

South Korea (/ˌsaʊθ kəˈriə/), officially the Republic of Korea (ROK, Hangul: 대한민국, Hanja: 大韓民國), is a sovereign state in East Asia, located on the southern portion of the Korean Peninsula. It is neighbored by the People's Republic of China (Mainland China) to the west, Japan to the east, North Korea to the north, and the East China Sea and Republic of China (Taiwan) to the south. South Korea lies in a humid continental and humid subtropical climate region with a predominantly mountainous terrain. Its territory covers a total area of 99,392 square kilometers and has a population of almost 50 million. The capital and largest city is Seoul, with a population of 10,421,782.
Archaeological findings show that the Korean Peninsula was occupied by the Lower Paleolithic period. Korean history begins with the founding of Gojoseon in 2333 BC by the legendary Dan-gun. Following the unification of the Three Kingdoms of Korea under Silla 668 AD, Korea went through the Goryeo Dynasty and Joseon Dynasty as one nation until the end of the Korean Empire in 1910, when Korea was annexed by Japan. After liberation and occupation by Soviet and U.S. forces at the end of World War II, the nation was divided into North and South Korea. The latter was established in 1948 as a democracy, though political turmoil, and periods of military rule and martial law, were to characterize much of the period until the foundation of the Sixth Republic in 1987.
After the invasion of South Korea by forces from the North on 25 June 1950, the resulting war between the two Koreas ended with an Armistice Agreement, but the border between the two nations is the most heavily fortified in the world. After the war, the South Korean economy grew significantly and the country had transformed into a major economy, a full democracy, and a regional power in East Asia.