South Korea, officially the Republic of Korea, is a sovereign state in East Asia constituting the southern part of the Korean Peninsula. South Koreans lead a distinctive urban lifestyle, as half of them live in high-rises concentrated in the Seoul Capital Area with 25 million residents.
The earliest neolithic Korean pottery dates to 8000 BC, with three kingdoms flourishing in the 1st century BC. The name Korea is derived from one of them, Goguryeo, which was one of the great powers in East Asia during its time, ruling most of the Korean Peninsula, Manchuria, some parts of the Russian Far East and Inner Mongolia, under Gwanggaeto the Great. Since the unification of the Korean kingdoms into Unified Silla and Balhae in the 7th century, Korea enjoyed over a millennium of relative tranquility under long-lasting dynasties. Koreans developed improved versions of many advanced innovations such as the metal movable type printing press, which used to print and publish the Jikji, the world's oldest extant movable metal type printed paper book in 1377.