evidence: Korea (known as 조선/Chosŏn in North Korea and 한국/Hanguk in South Korea) is a peninsula in East Asia occupied by two countries sharing a common culture, commonly called North Korea and South Korea. Korea is connected by land to Northeast China and the Russian Far East to the north, across the Yellow Sea from Beijing to its west, separated from Japan by the Sea of Japan (known as the 'East Sea' (동해, 東海) in Korea) to its east, and separated from Taiwan by the East China Sea to its south. [...] Wang Kŏn founded Koryŏ in 918 at Songdo (modern Kaesŏng, North Korea) and in 936 established a unified kingdom on the Korean peninsula. Wang Kŏn went to great lengths to absorb the people of the overthrown states, even accepting the survivors of Parhae, which had been destroyed by the Khitan (Liao). Proclaiming itself the successor of Koguryŏ, Koryŏ launched active campaigns to recover lost territory and clashed frequently with the Khitan in the north. Koryŏ eventually expanded its territory to the Yalu (Korean: Amnok) River.