Thinking that our girls needed some more room, and that a tree house would be fun, last weekend we created our doll sized tree-house.
The rooms are each 24" long by 20" tall by 18" deep. They stand on a real tree stump and have real limbs branching out each side. There is a swing on the left side for the girls to swing and a play yard for the pets on each section near the top.
This sits in the same room as the Dolls' House so it's kind of hard to get far enough away to take a good picture. Anyway, the girls seem to love it.