The coastline, c.1,700 mi (2,740 km) long, is fringed with islands (notably the Lofoten islands and Vesterålen) and is deeply indented by numerous fjords. Sognafjorden, Hardangerfjord, Nordfjord, and Oslofjord are among the largest and best known. From the coast the land rises sharply to high plateaus such as Dovrefjell and the Hardangervidda. Galdhøpiggen, in the Jotunheimen range, is the high point (8,098 ft/2,468 m); west of it lies Jostedalsbreen, the largest glacier field in Europe. The mountains and plateaus are intersected by fertile valleys, such as Gudbrandsdalen, and by rapid rivers, which furnish hydroelectric power and are used for logging. The Glåma, in the south, is the most important river. Because of the North Atlantic Drift, Norway has a mild and humid climate for a northern country. Most of the population is concentrated along the southern coast and valleys, where the chief cities-Oslo, Bergen, Stavanger, Kristiansand, and Drammen-are located. Farther north along the coast is Trondheim, and in the extreme north are Narvik, Tromsø, and Hammerfest. The majority of Norwegians are of Scandinavian stock, but in the northern county of Finnmark, Lapps and Finns predominate. The literary language of Norway for many years was Danish, from which Riksmål (officially Bokmål), one of the two official idioms of Norway, is derived (see Norwegian language and Norwegian literature). Landsmål (officially Nynorsk), the other official idiom, is similar. Frequent spelling reforms account for the variation in Norwegian place names. The Lutheran Church is the state church, but all other religions enjoy freedom of worship. The king nominates the nine bishops and other clergy of the Lutheran Church. The educational level in Norway is very high; the leading universities are in Oslo (founded 1811) and Bergen (founded 1946).