Liebig Museum

Justus Liebig was a famous chemist who taught in Gießen. He discovered things like the silver mirror, fertilization and meat extract. In the museum you can see his laboratory and once in a month they show an experiment which was first discovered by him.
Liebigstr. 12
http://www.liebig-museum.de/

Mathematikum

The Mathematikum was co-founded by the mathematic professor Albrecht Beutelspacher who also runs a show on German television about maths. The museum has the purpose to show children how much fun maths can be and how much it is integrated in our lives.
Liebigstr. 8
http://www.mathematikum.de/