As mentioned before, Bremerhaven has some interesting museums as Klimahaus and Auswandererhaus. Then there’s mostly Lower Saxony landscape, often flat, rather rural. read more
Bremen is smaller, has fewer sights to offer (two very nice art museums, though) and can be detected just by walking. Or taking the tram. If you go to a bar and need contact to locals, be sure to find help. read more
Bremen's narrow Böttcherstrasse, transformed between 1926-31 into a street of museums, is one of the city's most popular tourist attractions. Although only 100 meters long, its many examples of unusual expressionist architecture make it tremendous fun to explore (you can't miss the entrance - look for the Lichtbringer, an impressive gold sculpture above the "secret" archway). read more