Vättern is the second-largest lake by surface area in Sweden, after Vänern, and the sixth-largest lake in Europe. It is a long, finger-shaped body of fresh water in south central Sweden, to the southeast of Vänern, pointing at the tip of Scandinavia. Being a deep lake at 128 metres below sea level at its deepest point, Vättern is about 1/3 the surface area o…Vättern is the second-largest lake by surface area in Sweden, after Vänern, and the sixth-largest lake in Europe. It is a long, finger-shaped body of fresh water in south central Sweden, to the southeast of Vänern, pointing at the tip of Scandinavia. Being a deep lake at 128 metres below sea level at its deepest point, Vättern is about 1/3 the surface area of Vänern but in spite of this contains roughly 1/2 of its water.