The Tennen Mountains () is a small, but rugged, mountain range in the Northern Limestone Alps, which lies in front of the Eastern Alps for its entire length. It is a very heavily karstified high plateau, about 60 km² in area, with many caves. The range is located in Austria in the district of Salzburg near Bischofshofen. Some 37 square kilometres of the Tennen plateau are above the 2,000 metre line and that part of the range within the state of Salzburg was turned into a nature reserve in 1982. Extent and neighbouring ranges The outline of the Tennen range is formed: in the west by the Hagen Mountains, a part of the Berchtesgaden Alps, separated by the Salzach river. Here, at the northern end of the Lueg Pass, is the narrowest point of the Salzachöfen Gorge through the Limestone Alps. in the north and northeast by the River Lammer as far as the Rußbach stream, which descends from the Gschütt Pass. Beyond the Lammer is the Osterhorn Group (Salzkammergut Mountains) in the east by the Lammer valley as far as Lungötz, separating it from the Dachstein Mountains in the south it borders on part of the Salzburg Slate Alps right of the Salzach (Hochgründeck, Roßbrand) along the line from Karbach to St. Martin – Fritzbach – Salzach to Bischofshofen Valley settlements Werfen Pfarrwerfen Werfenweng Sankt Martin am Tennengebirge Annaberg-Lungötz Abtenau Scheffau am Tennengebirge Golling Summit The highest mountains in the Tennen are Raucheck () in the west and Bleikogel () in the east. The highest points all rise on the southern edge of the plateau, which falls away to the north. The most important peaks are: Raucheck (2,430 m) Lehnender Stein (2,402 m) Pfaffenleitnkopf (2,370 m) Werfener Hochthron (2,363 m) Fritzerkogel (2,360 m) Streitmandl (2,360 m) Schubbühel (2,334 m) Tiroler Kogel (2,324 m) Eiskogel (2,321 m) Brietkogel (2,316 m) Wieselstein (2,300 m) Scheiblingkogel (2,290 m) Hochkogel (2,283 m) Fieberhorn (2,278 m) Tauernkogel (2,247 m) Knallstein (2,234 m) Hochkarfelderkopf (2,219 m) Breitstein (2,161 m) Tagweide (2,128 m) Edelweißkogel (2,030 m) Geology The Tennen is a heavily karstified massif, composed mainly of Dachstein limestone lying on a foundation of Ramsau dolomite. Its southern foothills, along the line Lungötz–Werfenweng–Werfen, belong to an imbricate zone (Schuppenzone). This zone, made of Werfen Formation from the Lower Triassic and middle triadic dolomites (Anisian, Ladinian), is called the Werfen-St.-Martin Schuppen Zone. Caves There are numerous caves