Arctic Circle level, although in mountainous regions there is often no direct view of the true horizon. Only four million people live north of the Arctic Circle due to the severe climate; nonetheless, some areas have been settled for thousands of years by indigenous peoples, who today make up 10% of the region's population. Tens of thousands of years ago, waves of people migrated from eastern Siberia across the Bering Strait into North America to settle. The largest communities north of the Arctic Circle are situated in Russia, Norway and Sweden: Murmansk (population 307,257), Norilsk (175,365), Tromsø (71,295), Vorkuta (59,231) and Kiruna
Arctic policy of Russia in 1732. The Great Northern Expedition, which lasted from 1733 to 1743, was one of the largest exploration enterprises in history, organized and led by Vitus Bering, Aleksei Chirikov and a number of other major explorers. A party of the expedition personally led by Bering and Chirikov discovered southern Alaska, the Aleutian Islands and the Commander Islands, while the parties led by Stepan Malygin, Dmitry Ovtsyn, Fyodor Minin, Semyon Chelyuskin, Vasily Pronchischev, Khariton Laptev and Dmitry Laptev mapped most of the Arctic coastline of Russia (from the White Sea in Europe to the mouth of Kolyma River in Asia). The