Schwerin I did as a day trip from Berlin as as traveller1959 says the castle, on a lake, is gorgeous and the town is very pleasant.

Berlin is an always great idea! Especially if you like urbun stuff. There is so many things to do: clubbing, going through museums, just walking! By the way German food is awesome! I think Berlin is exactly what young people needs to try. If you love or do art you surely have to visit Museum for Contemporary Art in Berlin, that's in Mitte (Center). In my example, I didn't know anything about modern art so I ordered a tour with guide http://vivaster.com/ru/tour/hamburge...vate-tour-1434 . If you guys are active then you should know that Berlin is a bicycle heaven! wherever you go there are bicycle lanes everywhere. Night life is sooo cool! Have you ever heard about Berghain? Google it, I think you'll like it. Anyway, whatever you decide, have fun and enjoy your trip!

I usually just take the train (U-S-bahn) and going in any destination I think it's better way to see any city

http://www.fodors.com/community/euro...in-journal.cfm

An old thread but has some day trip info from me and others as well as various things about Berlin that are timeless.