7 Awesome Things To Do in Mannheim, Germany INTERNATIONAL. That’s how the city of Mannheim in Germany generally described. The label has been proved by the wide eras, depicting respective parts of the city. It might still sound vague for those who have never been in Mannheim; so if you are one of them, stick on this site and start realizing how this city can be your next destination! Here are things to do in Mannheim, Germany.