The fridge arrived on Friday. By Saturday morning the box had planning permission, and by Sunday it had a drawbridge.
No toy we have ever bought has been loved as hard as a large cardboard box with a door cut in it.
We learned three things: parcel tape beats glue, a grown-up should own the craft knife, and if you let the smallest builder choose the paint colours you will live with a pink-and-brown castle for a month. Worth it.