10% of Finland's surface is covered by lakes and, combined, they would submerge an area the size of Belgium.
In central and eastern parts of the country lies the Finnish Lake District, also known as the Lakeland, which forms the most extensive area of interconnected lakes in Europe, comprising tens of thousands of lakes.
There are 309 separate lakes each covering more than 10 km² in Finland, accounting for 65% of the country's total lake area. With their diverse range of fish species, these major lakes are the most significant lakes in terms of fishing. People generally go fishing on these lakes on boats.
Lakes carved out by the Ice Age
Finland's lakes were formed into grooves carved out in the ground by ice in the aftermath of the latest Ice Age.
Typical characteristics include shallow waters, labyrinthine shapes and an abundance of islands. Lake bottoms vary considerably and many lakes have shoals. The deepest spots of major lakes are in the range of 100 metres.
Some lakes have formed into crustal depressions, while there are also some with craters of meteors that crashed to earth thousands or millions of years ago lying at their bottoms. Such crater lakes include Lakes Suvasvesi, Lappajärvi, Keurusselkä, as well as Paasvesi in the Lake Saimaa area.
There are plenty of wetland areas in Finland and, as a result, a considerable proportion of water bodies are more or less brownish in colour. However, there are also many rugged and limpid lakes.
Regardless of colour, lake waters are mostly pure. Lush and muddy lakes can be found in the vicinity of the agricultural areas of Southern Finland in particular.