The Alps are one of the great mountain range systems of Europe stretching approximately 1,200 kilometres (750 mi) across eight Alpine countries from Austria and Slovenia in the east, Switzerland, Liechtenstein, Germany, France to the west and Italy and Monaco to the south. The flora of the Alps are diverse. In the mountains, the vegetation gradually changes with altitude, sun exposure, and location on the mountain. There are five successive life zones, each with distinct landscapes and vegetation characteristics: premontane, montane, subalpine, alpine, and alvar.^{[citation needed]}