Thuringian Forest, range of forested hills and mountains in Germany, extending in an irregular line from the neighbourhood of Eisenach in west-central Thuringia southeastward to the Bavarian frontier, where it merges with the Franconian Forest. Its breadth varies from 6 to 22 miles (10 to 35 km). It nowhere rises into peaks, and, of its rounded summits, the highest, Beerberg, rises only 3,222 feet (982 m). This range encloses many charming valleys and glens; the most prominent feature of its scenery is formed by the forests, chiefly of pines and firs. The northwest part of the system is the loftier and the more densely wooded as well as the more beautiful. The southeast part is the more populous and industrial.
The crest of the Thuringian Forest, from the Werra to the Saale rivers, is traversed by the Rennsteig, a broad path of unknown antiquity. The name probably means “frontier path,” and the path marked in fact the historical boundary between Thuringia and Franconia. It may be also regarded as part of the boundary line between north and south Germany, for dialect, customs, local names, and native costume have traditionally been different on the two sides. The area was once an iron-mining centre (until the 16th century) but is now largely given over to small industries (toy making, wood carving, and glass and china manufacturing) and to tourism in such resorts as Eisenach, Friedrichroda, Giessübel, and Oberhof.