If there's something to climb Adelaide will find it.
We have in this house a small cubby, about four feet square (give or take) and tall enough to need a step stool to reach the top. The previous owners used it for storing summer chairs. I think the original use was intended to store firewood since it's next to the fireplace. The girls saw it and immediately claimed it for a club house. The walls are bare plywood and I had the idea of getting old wallpaper books from the stores and choosing pages and pasting them to the walls in a patchwork. Something to pretty it up.
We each took turns rolling paste onto the backs of the sheets we cut out of the books.
Adelaide's color choices were bright and mostly blues. She likes blue.
We're chillin' with a bowl of popcorn and a movie right now but Adelaide just asked me to read the books we got at the library this morning so I have to go....