Glaciers, Lakes, and Rivers
During the last great Ice Age, the Alps were covered by massive mountain glaciers, remnants of which are found at high elevations. In the Bernese Alps is the Aletsch Glacier, with an area of 66 square miles (171 km 2). Another large glacier is the Mer de Glace (“Sea of Ice”) on the northern slope of Mont Blanc.
The Ice Age glaciers scooped out broad valleys. In some of these glacial depressions, large, deep lakes were formed. Among those on the northern edge of the Alps are Lakes Geneva, Lucerne, and Constance. On the southern side are Lakes Maggiore, Lugano, Como, and Garda.
Three of the largest rivers of Europe—the Rhine, Rhône, and Po—originate in the Alps. Major southern tributaries of the Danube originate here as well. There are also hundreds of small, swift streams, some with spectacular waterfalls.