Norways extensive coast, fringed with innumerable small islands, stretches from the Artic Ocean to the North Sea. Inland it borders on Sweden, Finland, and Russia. It is mountainous, rising to 2,470 m (8,104 feet) in the Jotunheimen range. In the morth, it is light all 24 hours in high summer, and equally dark in winter. Its warm climate is caused by the Gulf Stream, which usually keeps the Fiords from freezing, The south is barren moorland plateau cut by forested valley's.