Three-thousander
Three-thousanders are mountains with a height of between , but less than above sea level. Similar terms are commonly used for mountains of other height brackets e. g. four-thousanders or eight-thousanders. In Britain, the term may refer to mountains above . Climatological significance. In temperate latitudes three-thousanders play an important role, because even in summer they lie below the zero degree line for weeks. Thus the chains of three-thousanders always form important climatic divides and support glaciation - in the Alps the contour is roughly the general limit of the "nival step"; only a few glaciated  mountains are under (the Dachstein, the easternmost glaciated mountain in the Alps, is, at , not a three-thousander). In the Mediterranean, however, the three-thousanders remain free of ice and, in the tropics, they are almost insignificant from a climatic perspective; here the snow line lies at around to , and in the dry continental areas (Trans-Himalayas, Andes) it may be up to high. Alpinism. The designation "three-thousander" is often used for touristic reasons where only a few individual summits exceed this height – e. g. in the Southern Alps, in the eastern part of Austria, in the Limestone Alps , in the Pyrenees or the rest of Europe. For example, the Parseierspitze in the Lechtal Alps at is the only three-thousander in the Northern Limestone Alps. In the Alps or Pyrenees, expeditions to areas of over , with their often steep mountainsides and sudden changes in weather conditions, require mountaineers to have considerable experience and weatherproof equipment, which distinguishes them from ascents of many two-thousanders. The term "easy three-thousander" ("Leichte Dreitausender") or "Hikable three-thousander" ("Wanderdreitausender") describes mountains above with routes that do not pose any particular challenges. Typical "easy" three-thousanders, for example, include the Piz Boe  () in South Tyrol, which is an hour's walk from the Pordoi Cable Car, or the high Piz Umbrail, accessible from the Umbrail Pass. Amongst the highest easy three-thousanders in the Alps are the Üsser Barrhorn () in the Wallis Alps and the Monte Vioz (, southern Ortler Alps). For ascents of these mountains the main risk is the lack of acclimatisation at these heights. The highest technically accessible three-thousanders in the Alps (and also the highest cable cars in Europe) are the Klein Matterhorn () near Zermatt and the Aiguille du Midi () on Mont Blanc. Alps. The easternmost three-thousanders  in the Alps are in the Hafner Group in the east of the High Tauern (from west to east: Großer Hafner , Lanischhafner , Lanischeck , Großer or Malteiner Sonnblick , and Mittlerer Sonnblick ). The northernmost 3,000ers are in the northern chains of the High Tauern, Zillertal, Ötztal, and Stubai Alps (as well as the Parseierspitze in the Lechtal Alps). The southernmost 3,000ers are on the main chain of the Maritime Alps (Argentara Group), the Mercantour and the Pelat Group with about a dozen main peaks over above sea level. In the eastern Alps the southern boundary lies in the Bergamo Alps (3 main  summits), of the Adamello–Presanella Group (about a dozen) and the Dolomites (about 50 peaks). So the ranges of the Alps that contain mountains over the 3,000 m mark comprise roughly two thirds of the area, the 3,000er zone in the Western Alps coming much closer to the edge of the Alpin region than in the Eastern Alps with their extensive system of foothills. The easternmost 3,000er is over from the Pannonian Alpine perimeter, the westernmost only about from the Rhone valley. A large part of this sensitive, high Alpine region is protected by conservation areas, but it also forms  the touristic heart of the Alps. Switzerland, France, Austria, and Italy have many hundreds of Alpine peaks over 3,000 metres. Germany's Zugspitze, at , just falls below the line, whilst Slovenia's Triglav is well under it. Liechtenstein, despite being the only country lying entirely within the Alps, has no 3,000ers on its territory. Rest of Europe. Apart from the Alps, the dominant range in Europe – if one excludes the Caucasus, which otherwise, in Mount Elbrus (5,642 m), would have the highest mountain in the continent – only the following ranges have three-thousanders: Musala at 2,925 m, the highest mountain  in southern Europe (i.e. excluding the Iberian Peninsula), does not come close to the mark. The Apennine Mountains reach 2,912 m in the Gran Sasso. The Dinaric Alps, Carpathian Mountains, Sistema Central and Cantabrian Mountains are less than 2,700 m high, and the other ranges in Europe are below 2,500 m.