Korea: Sarang Hae in Blossom
The Korean Peninsula is a peninsula located in East Asia. It extends southwards for about 1,100 km (680 mi) from continental Asia into the Pacific Ocean and is surrounded by the Sea of Japan (East Sea) to the east and the Yellow Sea (West Sea) to the west, the Korea Strait connecting the two bodies of water. To the northwest, the Amnok River separates the peninsula from China and to the northeast, the Duman River separates it from China and Russia. Notable islands include Jeju Island, Ulleung Island, Dokdo.
The southern and western parts of the peninsula have well-developed plains, while the eastern and northern parts are mountainous. The highest mountain in Korea is Mount Paektu (2,744 m), through which runs the border with China. The southern extension of Mount Paektu is a highland called Gaema Heights. This highland was mainly raised during the Cenozoic orogeny and partly covered by volcanic matter. To the south of Gaema Gowon, successive high mountains are located along the eastern coast of the peninsula. This mountain range is named Baekdudaegan. Some significant mountains include Mount Sobaek or Sobaeksan (1,439 m), Mount Kumgang (1,638 m), Mount Seorak (1,708 m), Mount Taebaek (1,567 m), and Mount Jiri (1,915 m). There are several lower, secondary mountain series whose direction is almost perpendicular to that of Baekdudaegan. They are developed along the tectonic line of Mesozoic orogeny and their directions are basically northwest.
Unlike most ancient mountains on the mainland, many important islands in Korea were formed by volcanic activity in the Cenozoic orogeny. Jeju Island, situated off the southern coast, is a large volcanic island whose main mountain Mount Halla or Hallasan (1950 m) is the highest in South Korea. Ulleung Island is a volcanic island in the Sea of Japan, the composition of which is more felsic than Jeju-do. The volcanic islands tend to be younger, the more westward.
Check more at: https://en.wikipedia.org/wiki/Korea