The western part of the region is characterized by the small number of watercourses, majority of which are rivers (lakes being mostly located in the eastern part). The scenery is typically flat, the percentage of mires and marshland is great, and the population is mostly situated close to the rivers.
The southern region with its river valleys is typically farming country, whereas the north-eastern parts of the area are characterized by the presence of wilderness, hill and fell country, and scarcity of population.
Distinctive environmental features around the coastal areas of the Bothnian Bay are the land uplift phenomenon, low ground level and long lasting ice cover (approximately 7 months annually).
The entire region is also well known for its mires covering wide ecological range from bogs to rich fens, spring-fed mires and flooded swamps. Almost all mire plant and bird species recorded from Finland can be found in these mires.