My look up photo is taken from the ground floor (which you can't see), which included sleeping, eating and lounging areas. It was covered with a thick layer of cut grass, which made it almost completely waterproof and very warm and snuggly. The first level you can see is a dance floor "for the fairies to have lots of discos". Can you see the mirror ball? How cool is that?
And the top layer, which you can see the bottom of, with the mirror ball hanging from it ... it contained nothing but a thick layer of soft grass and leaves. "What's that bit for?" I asked. They answered "It's a secret place for snogging!"