English: Sometime around 10,000 years ago, massive glaciers carved the landscape of what is now Sweden. The slow grinding action of several-mile-thick ice created mountains in the north of the country and, in the south, a flatter landscape with deep depressions—which are now lakes—in the south. The two largest lakes in Sweden, Lake Vänern and Lake Vättern, are two examples of the power of ice over the landscape.

Situated in southwestern Sweden, and with a surface are of about 5,650 square kilometers (2,180 sq mi) Lake Vänern claims the title of the largest lake in Sweden as well as the third-largest lake in Europe. It has a coastline of 4,800 km (2,983 mi), much of which is rocky and wooded, but also hosts several cities and towns that are important as fishing and industrial centers. Within the lake, there is a complex freshwater archipelago containing more than 22,000 islands, islets, and boulders. The largest island, Djuro, is located in the center of the lake and has been named a national park.

The longer, thinner, Lake Vättern sits to the southeast of Vänern. With a surface are of 1,912 square km (738 sq mi), Vättern is the second-largest lake in Sweden and the sixth-largest in Europe. It provides drinking water for more than 250.000 people and is a popular destination for those seeking to view or swim in the crystal-clear waters.

The Moderate Resolution Imaging Spectroradiometer (MODIS) on board NASA’s Aqua satellite acquired a true-color image of Lake Vänern and Lake Vättern on September 2, 2021.