Archipelagoes of the Baltic Sea

part of the Baltic Sea

archipelago in Estonia

Ertholmene (formerly spelled Ærtholmene) is a small archipelago in Denmark. The largest island is Christiansø, whose name is often used with reference to the entire archipelago. Ertholmene are situated northeast of Gudhjem, Bornholm, and include Denmark's easternmost point. Two of the islands, Christiansø and Frederiksø, are inhabited, with a combined permanent population () of 90. The archipelago has a total area of . Its name is derived from the Danish for "pea islands".

Åboland () is a sub-region in the archipelago of the Southwest Finland region in south-western Finland.

Swedish archipelago in the Baltic Sea

the waters between Funen, Ærø and Langeland in Denmark