I have been aware of this site for a while now, and I thought that I would share it with anyone who may not have come across it. Mini Efteling opened in 1985 and was/is managed mainly by children, with a little help from older volunteers. Tours of Mini Efteling last about 3 hours and cost €5, and if you want to visit, you are urged to make a reservation in advance.
Here is a slideshow of some of the things you can see at Mini Efteling.
It looks like a really fun place to visit, and it isn’t too far from Efteling!