Sion (German Sitten, Latin Sedunum) is the capital of the Swiss canton of Valais. As of December 2009 it had a population of 29,718.
Landmarks include the Basilique de Valère and Château de Tourbillon.
The Alps (French: Alpes; German: Alpen; Italian: Alpi; Romansh: Alps; Slovene: Alpe) is the name for one of the great mountain range systems of Europe, stretching from Austria and Slovenia in the east, through Italy, Switzerland, Liechtenstein and Germany to France in the west. The word "Alps" was taken via French from Latin Alpes (meaning "the Alps"), which may be influenced by the Latin words albus (white) or altus (high) or more likely a Latin rendering of a Celtic or Ligurian original.
The highest mountain in the Alps is Mont Blanc, at 4,808 metres (15,774 ft), on the Italian-French border. All the main peaks of the Alps can be found in the list of mountains of the Alps and list of Alpine peaks by prominence.
The Alps are generally divided into the Western Alps and the Eastern Alps. The division is along the line between Lake Constance and Lake Como, following the Rhine. The Western Alps are higher, but their central chain is shorter and curved; they are located in Italy, France and Switzerland. The Eastern Alps (main ridge system elongated and broad) belong to Austria, Germany, Italy, Liechtenstein, Slovenia and Switzerland.
The Alps are a classic example of what happens when a temperate area at lower altitude gives way to higher elevation terrain. Elevations around the world which have cold climates similar to those found in polar areas have been called alpine. A rise from sea level into the upper regions of the atmosphere causes the temperature to decrease. The effect of mountain chains on prevailing winds is to carry warm air belonging to the lower region into an upper zone, where it expands in volume at the cost of a proportionate loss of heat, often accompanied by the precipitation of moisture in the form of snow or rain.