Baltic Sea

Geography

 * Borders Sweden, Finland, and Germany
 * Connected to the North Sea by the Kiel Canal
 * Mouth of the Neva River

History

 * The Danzig Corridor gave Poland access
 * The Schmalkaldic and Hanseatic Leagues focused here
 * Fortifications like Fronstadt were built on the mouth of the Neva following Russian expansion in the Great Northern War
 * Named Mare Suebicum after the Suebi tribe in Roman times
 * The RAF sank the prison ship SS Cap Arcona
 * Led to the deaths of 5000 war prisoners