How do I build a cardboard castle with children? First order 10 easels (or a few fridges, TVs or DIY-furniture) so that there’s enough cardboard to build big. Secondly: empty the floor and wear old clothes. Provide tape, rope, poster paint, scissors, brushes, and plates for mixing paint on. And finally: throw out any expectations of a “real” castle with battlements and towers and so forth. A pink beauty like this:

you only achieve when you hold their hand every step of the way. And then you’ll miss out on unexpected inventions. In this case Groeten van Marc held an open day and the result was a kind of new religion / political party / world order with matching symbols and war strategies (landmines made of bubble wrap, styrofoam shields, flags with handprints).