Are you starting you studies in Hamburg this winter semester?  Then you can get a free card, called  "Meine Freikarte" for some museums and theaters. It's awesome!! You can go 30 minutes before the play starts and ask if there are any tickets left and then you get them for free or you can go to a few museums whenever you want always for free! If you want one you should ask your Asta. In Harburg it is in building E, called Lindwurm.

This card is valid from 1. october -31. december