The term 'Norwegian Seaport' can be broken down into two crossword solutions: Oslo (4 letters) and Vadso (5 letters). Oslo is the capital and most populous city of Norway, located in the southeastern part of the country. It is a major center for maritime industries and maritime trade in Europe. Vadso is a port city in northern Norway, located on the Barents Sea coast. It is an important fishing port and has a large shipbuilding industry.