Sea of Åland in the context of "Archipelago Sea"

The Gulf of Bothnia (/ˈbɒθniə/, Swedish: Bottniska viken, Finnish and Meänkieli: Pohjanlahti) is divided into the Bothnian Bay, the (North) Kvarken and the Bothnian Sea, and it is the northernmost arm of the Baltic Sea, between Finland's west coast (Ostrobothnia (East Bothnia)) and the northern part of Sweden's east coast (Västerbotten (Westrobothnia, West Bothnia) and Norrbotten (North Bothnia)). In the south of the gulf lies Åland, between the Sea of Åland and the Archipelago Sea.

The Bothnian Sea (Swedish: Bottenhavet; Finnish: Selkämeri) links the Bothnian Bay (also called the Bay of Bothnia) with the Baltic proper. Kvarken is situated between the two. Together, the Bothnian Sea and Bay make up a larger geographical entity, the Gulf of Bothnia, where the Bothnian Sea is the southern part. The whole Gulf of Bothnia is situated between Sweden, to the west, Finland, to the east, and the Sea of Åland and Archipelago Sea to the south. The surface area of the Bothnian Sea is approximately 79,000 square kilometres (30,500 sq mi). The largest coastal towns, from south to north, are Rauma and Pori in Finland, and Gävle and Sundsvall in Sweden. Umeå (Sweden) and Vaasa (Finland) lie in the extreme north, near Bothnian Bay.

South Kvarken (Finnish: Ahvenanrauma, Swedish: Södra Kvarken) is the narrowest stretch of sea between Finnish Åland and Sweden, forming a strait connecting the Sea of Åland and the Bothnian Sea of approximately 30 km (18.5 mi) across.

60°08′57″N 19°10′21″E / 60.1492°N 19.1725°E / 60.1492; 19.1725

Grisslehamn is a locality and port located on the coast of the Sea of Åland in Norrtälje Municipality, Stockholm County, Sweden. The locality had 249 inhabitants in 2010.

The name Grisslehamn was first mentioned in a document from 1376 about the mail route between Sweden and Finland. This Grisslehamn was located some 20 km south of today's location. In the mid-18th century, most of the old village was destroyed in a fire, and it was decided to move Grisslehamn to its current location to make the mail route shorter. Conveying mail by row boat from Sweden to the Åland islands, whence it was transported to the Finnish mainland, was, together with fishing, one of the most important sources of income for the inhabitants of Grisslehamn and other parts of Roslagen for a long time, until steam ships took over the mail routes in the early 20th century.