Brussels is the official seat of the European Commission and home to several other European institutions so a visit here is highly recommended.
The Parlamentarium, a large area devoted to explaining what the institutions do, the land mass covered and a whole lot more is highly recommended. There are originals and facsimiles of important treaties, and lots of hands-on stuff to engage children and adults alike. The price is right too – it’s free and open all year round. About twice a year, the temporary exhibition changes and space is given over to artists and exhibitors working to a specific theme.
You’ll need to take a photo ID with you to register.