South Korea is a sovereign state in East Asia, constituting the southern part of the Korean Peninsula. Officially, its territory consists of the whole Korean Peninsula and its adjacent islands, which are largely mountainous. 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 capital Seoul is the world’s sixth leading global city with the fifth largest economy and is the seventh most sustainable city in the world.