3. The Lyngen AlpsLyngen Municipality Tromsø is a municipality in Troms county, Norway. The administrative centre of the municipality is the city of Tromsø. Outside Norway, Tromso and Tromsö are alternative spellings of the name. Tromsø lies in Northern Norway. The 2,521-square-kilometre municipality is the 18th largest by area out of the 422 municipalities in Norway. Tromsø is the 9th most populous municipality in Norway with a population of 74,541. The municipality's population density is 30.1 inhabitants per square kilometre and its population has increased by 15.6% over the last decade. It is the largest urban area in Northern Norway and the third largest north of the Arctic Circle anywhere in the world . Most of Tromsø, including the city centre, is located on the island of Tromsøya, 350 kilometres north of the Arc... From Wikipedia, the free encyclopedia.