Finland is a northern European nation defined by its glacial history. During the last Ice Age, massive glaciers carved the land, resulting in a landscape that is roughly 10% water and 75% forest. The capital, Helsinki, is a coastal city on the Baltic Sea. Finland shares land borders with Sweden, Norway, and Russia. A unique geographical phenomenon in Finland is post-glacial rebound; the land is still rising at a rate of about 7 millimeters per year in some areas as it recovers from the weight of ancient ice. This means Finland's land area is actually increasing over time. The country is also home to the Saimaa lake system, which contains the endangered Saimaa ringed seal, one of the world's rarest seals. In the far north, the Sami people inhabit the region of Lapland, where the sun does not set for several weeks during the summer solstice and does not rise during the winter solstice.