If you're in Brussels and into the European Union issues, you should pay a visit to the Parlamentarium. It is a visitor's center located in the European Parliament, to which you can access for free and have a tour with one of the audio-guides provided (available in all 23 EU languages). The visit is very interactive, as you can pass your guide in some points of the exhibition and hear detailed explanations on some specific aspects, see pictures, etc. In the end you can watch a short movie about how the European Parliament works in a room with a 360 degree screen. The whole visit should take you about 1h and I really enjoyed going there, so I reccommend it!