East Asia’s South Korea, officially known as the Republic of Korea (ROK), is a nation. Although it also claims the land boundaries with China and Russia, it makes up the southern portion of the Korean Peninsula and borders North Korea along the Korean Demilitarized Zone. The Yellow Sea forms the nation’s western border, while the Sea of Japan delineates its eastern border. The only recognized government over the whole peninsula and its neighboring islands, according to South Korea, is its own. Of its 51.96 million inhabitants, half reside in the Seoul Capital Area, which is the sixth most populated metropolitan area globally. Other significant cities are Incheon, Daegu, and Busan.