Tromsø, town in northern Norway, capital of Troms County. Tromsø is located on the island of Tromsøy off the northwestern coast of mainland Norway, in the Norwegian Sea. It is the largest Norwegian town north of the Arctic Circle. Troms County includes the adjacent mainland; Tromsøy Island is linked to the mainland by a bridge. As the county seat, Tromsø is the administrative, communications, cultural, and educational center of northern Norway. It is also a fishing port with fish-processing industries. Other industries include shipbuilding, brewing, prefabricated houses, high technology, and tourism. The town is served by an airport and is a starting point and support base for arctic expeditions. A meteorological station, an institute studying the aurora borealis, or northern lights, and the University of Tromsø (founded in 1968) are all located in Tromsø. Tromsø was founded in the mid-13th century, and granted a town charter in 1794. The Norwegian government was based in Tromsø for a short period during World War II (1939-1945). The modern Tromsdal Church, built in 1965, is known as the “Cathedral of the Arctic;” there is also a wooden cathedral (1861) in the center of the town. Tromsø Museum contains an aquarium, and is devoted to natural history and to the history and culture of the Saami (Lapp). Population (2005 estimate) 63,392.