To its west are the Yellow Sea and Korea Bay, and to its east lies Japan across the Sea of Japan (East Sea of Korea). The highest point in North Korea is Baekdu Mountain at 2,744 metres (9,003 ft). The longest river is the Amnok (Yalu) River which flows for 790 kilometres ,North Korea's climate is relatively temperate.
"The water temperature ranges from 20 C in June to 27 C in September to 20 C in December to 15 C in March. You can dive all year round. Visibility is best in autumn and winter when it can reach 25 m.
Early European visitors to Korea remarked that the country resembled "a sea in a heavy gale" because of the many successive mountain ranges that crisscross the peninsula. Some 80% of North Korea is composed of mountains and uplands, separated by deep and narrow valleys. All of the Korean peninsula's mountains with elevations of 2,000 meters (6,600 ft) or more are located in North Korea. The coastal plains are wide in the west and discontinuous in the east. A great majority of the population lives in the plains and lowlands. According to a United Nations Environmental Programme report in 2003, forest covers over 70 percent of the country, mostly on steep slopes. The longest river is the Amnok (Yalu) River which flows for 790 kilometres (491 mi).
The highest point in North Korea is Baekdu Mountain, a volcanic mountain which forms part of the Chinese/North Korean border with basalt lava plateau with elevations between 1,400 and 2,744 meters (4,593 and 9,003 ft) above sea level.The Hamgyong Range, located in the extreme northeastern part of the peninsula, has many high peaks including Kwanmobong at approximately 2,541 m (8,337 ft). Other major ranges include the Rangrim Mountains, which are located in the north-central part of North Korea and run in a north-south direction, making communication between the eastern and western parts of the country rather difficult; and the Kangnam Range, which runs along the North Korea–China border. Mount Kumgang, or Diamond Mountain, (approximately 1,638 metres or 5,374 feet) in the Taebaek Range, which extends into South Korea, is famous for its scenic beauty.