The Museum für Kommunikation is a touchy-feely museum displaying the history of communication, including tips on how to make invisible ink and decipher codes. It's a winner with kids, and it won't cost you a penny unless you visit the excellent café.
The Museum für Kommunikation (Communications Museum) entertains kids with its hands-on exhibits and invisible ink, and the Cold War espionage equipment will bring out the 007 in adults.