Landforms of Ostrobothnia (administrative region)

Kvarken ( (as opposed to South Kvarken); ) is the narrow region of the Gulf of Bothnia separating the Bothnian Bay (the inner part of the gulf) from the Bothnian Sea. The distance from the Swedish mainland to the Finnish mainland is around , while the distance between the outermost islands is only . The water depth in the Kvarken region is only around . The region also has an unusual rate of land rising at almost a year.

prehistoric site in Kristinestad, Finland

Replot () is an island in the Kvarken ("The Throat"), the narrowest part of the Gulf of Bothnia in the northern part of the Baltic Sea. It has about 2,100 inhabitants, almost only Swedish-speaking. The size is about , one of the largest islands of Finland. Replot was an independent municipality until 1973, when it was consolidated to the municipality of Korsholm, near Vaasa.

thumb|250px|View of the basin of the crater remnant from Öjberget, a hill that belongs to the Rim (crater)|crater rim Söderfjärden is a polder in Ostrobothnia, western Finland, 10 kilometres south of the town of Vaasa. The plain is in an impact crater dating back to more than 640 million years ago (Proterozoic, near the end of the Cryogenian). The crater's diameter is and its maximum depth is . It is filled with Cambrian sandstones leaving only the outer rim visible. There is also a central uplift, which is buried. After rising from the sea due to post-glacial rebound, Söderfjärden was a wetla

Valsörarna (in Swedish) or Valassaaret (in Finnish) is a small archipelago in Korsholm, Finland, located in the Kvarken region of the Gulf of Bothnia. The islands are the last you see when going by boat or ferry from Vaasa, Finland to Umeå, Sweden. The archipelago is detached from Korsholm's main Replot-Björkö archipelago. They are uninhabited and there is no road access. However, they are an important bird sanctuary, frequented by birdwatchers and ornithologists. They are included in the UNESCO World Heritage List along with the High Coast of Sweden and the archipelago of Kvarken, for exhibit

island in Korsholm, Finland

thumb|right|Vaskiluoto highlighted on the map of Vaasa Vaskiluoto (Swedish: Vasklot) is a Finnish island in the Gulf of Bothnia, immediately in front of the city centre of Vaasa, Finland. It is connected to the mainland by the Vaskiluoto road and rail bridge, and has a surface area of .