Alps

The Alps are a long line of tall mountains in Europe.

Their tops are white with snow and ice. Green meadows and pretty lakes sit in the valleys below. Many big rivers start here, high in the mountains.

The Alps are a giant arc of mountains in the middle of Europe. They begin on the warm Mediterranean coast near Nice, in France, curve north to Lake Geneva, and then run east all the way to Vienna, in Austria. Britannica measures them at about 1,200 kilometers long and more than 200 kilometers wide at their broadest point.

The Alpine Convention, a treaty the Alpine countries signed to protect the mountains together, names eight Alpine countries: Austria, France, Germany, Italy, Liechtenstein, Monaco, Slovenia and Switzerland. The highest peak is Mont Blanc, in the Western Alps, at 4,807 meters by Britannica's figure. Some of Europe's biggest rivers, including the Rhine and the Rhône, begin in the Alps.

Britannica describes the Alps as one small segment of a broken chain of mountains that runs from the Atlas Mountains of North Africa across southern Europe and Asia to beyond the Himalayas. The Alps run from the subtropical coast near Nice north to Lake Geneva, then east-northeast to the Vienna Woods, where they meet the Danube. They are about 1,200 km long, more than 200 km wide between Garmisch-Partenkirchen and Verona, and cover more than 207,000 km².

The range is divided into Western, Central and Eastern Alps. The highest summits stand in the west: Mont Blanc reaches 4,807 m by Britannica's figure, and the Central Alps hold the Dufourspitze, Weisshorn, Matterhorn and Finsteraarhorn. Farther east the peaks are lower; Austria's highest, the Grossglockner, is 3,798 m. Waters from the Alps reach four seas: the North Sea by the Rhine, the Mediterranean by the Rhône, the Adriatic by the Po, and the Black Sea by the Danube. Britannica adds that, tropical climates apart, most of Earth's climates can be found somewhere in the Alps.

Different plants grow at different heights in the Alps.

Low down there are leafy trees. Higher up there are pine trees. Higher still, cows and sheep eat grass in summer meadows. Ibex climb the rocks, and marmots sleep in burrows all winter.

Climb an Alpine mountain and you pass through different zones of life. Valley floors and low slopes have leafy trees such as oak, beech and birch. Higher up, the forests are mostly spruce, larch and pine. Above the trees, and below the snow that never melts, lie summer meadows, where farmers graze sheep and cows. Britannica explains that these mountain pastures are called alpages, the word that gave the Alps their name.

The Alpine Convention counts about 30,000 animal species and 13,000 plant species in the Alps. The ibex, a wild goat, and the goatlike chamois leap across steep rock. Marmots hibernate in tunnels underground. The mountain hare and the ptarmigan, a bird, turn white for winter. Lynx, brown bears and bearded vultures have been brought back to parts of the Alps.

Britannica describes vegetation zones set by elevation and climate. Deciduous trees such as linden, oak, beech, chestnut and birch grow on valley floors; spruce, larch and pine dominate the higher conifer forests, with spruce reaching about 2,200 m in the Western Alps and larch about 2,500 m. Near the tree line the slow-growing Arolla pine can live 350 to 400 years, exceptionally 800, and cutting it is strictly controlled. Above the trees lie the alpages, meadows grazed in summer, which Britannica names as the source of both the range's name and its vegetation zone. Austrian researchers estimated that the upper limits of Alpine plants rose about 3 feet (roughly 1 m) per decade in the 20th century.

The Alpine Convention counts about 30,000 animal and 13,000 plant species. Ibex and chamois are suited to craggy slopes, marmots hibernate in underground galleries, and the mountain hare and ptarmigan turn white in winter. Population pressure has caused some species to disappear, but lynx, brown bear and bearded vulture have been successfully reintroduced, and several national parks protect the native fauna.

People have lived in the Alps for a very long time.

Long ago they built roads over high mountain passes. Today trains go through long tunnels under the mountains. People speak many languages in the Alps.

People have lived in the Alps for tens of thousands of years. In Italy's Camonica Valley, about 20,000 pictures carved into rock show more than 2,000 years of life there. Later, the Romans widened mountain trails into roads over passes such as the Brenner and the Great St. Bernard.

For centuries many valleys were quite cut off from each other. Railways with long tunnels changed that. Today many people in the Alps speak French, Italian, German or Slovenian, and in some valleys Romansh, Ladin or Friulian. Visitors began coming in the 1800s, and since World War II tourism has grown huge, with millions of visitors in summer and winter. In 1991 the Alpine countries signed the Alpine Convention to protect the mountains together.

Britannica dates the first people in the Alps to Paleolithic hunters 60,000 to 50,000 years ago. The Camonica Valley in Italy holds some 20,000 rock engravings covering more than 2,000 years of habitation, and rich finds at Hallstatt, a small settlement in Upper Austria, made its name a byword for the late Bronze and early Iron ages in Europe. Celtic peoples opened high passes for trade; the Romans enlarged them into narrow roads, and passes such as the Great St. Bernard, Splügen and Brenner linked their outposts.

The Industrial Revolution and railways through great tunnels ended the isolation of many valleys. Hydroelectric power from the late 19th century drew factories to the lower valleys, and tourism, modest in the 19th century, became a mass phenomenon after World War II. The cost has been high: Britannica lists poorer air, water pollution, erosion from ski slopes and roads, and weakened forests, and calls the Alps likely the most threatened mountain system in the world. The Alpine Convention, signed in 1991 and in force since 1995, joins the eight Alpine countries and the European Union; it describes itself as the first international treaty to protect an entire mountain range.

The Alps have big rivers of ice called glaciers.

The weather is getting warmer, so the ice is melting. Some small glaciers are already gone. Scientists measure the ice every year.

The Aletsch Glacier in Switzerland is, UNESCO says, the largest and longest glacier in Europe. Glaciers like it store water as ice. Britannica explains that their summer meltwater helps fill the deep reservoirs of hydroelectric power stations.

But the Alps are warming. The Alpine Convention reports that temperatures there have risen by about 2 °C since the 1800s. Swiss scientists who measure the glaciers every year reported that in 2025 Switzerland's glaciers lost about 3 percent of their ice. Since 2015 they have lost about a quarter of their ice, and more than 1,000 small glaciers have already disappeared.

UNESCO describes the Jungfrau-Aletsch-Bietschhorn site, listed in 2001 and enlarged to 82,400 ha, as the most glaciated part of the European Alps, holding the Aletsch Glacier, the largest and longest in Europe. Its varying rates of glacier retreat illustrate climate change, and plants colonizing the ground the ice leaves behind provide an outstanding example of plant succession. Britannica notes that summer runoff from Alpine glaciers fills deep reservoirs used for hydroelectric power.

The Alpine Convention gives a temperature rise of about 2 °C in the Alps since the 19th century. GLAMOS, Switzerland's glacier monitoring network, and the Swiss Commission for Cryosphere Observation reported that a low-snow winter and heat waves in June and August cost Swiss glaciers almost 3 percent of their volume in 2025, the fourth-largest loss since measurements began, after 2022, 2023 and 2003. Glaciers across Switzerland have lost a quarter of their volume since 2015, and more than 1,000 small glaciers have vanished. GLAMOS director Matthias Huss added that shrinking glaciers also help destabilize mountains.