Recently I was visiting Bellingham, WA and saw this amazing tree house sculpture on display in a store window. It is a giant fantasy doll/ tree house about 4-5 feet tall, called The Fairy Castle. The house and its furnishings are made mostly if not entirely out of scraps of natural materials such as driftwood, shells and moss. It is not really a dollhouse in that while you can move the furniture around and so forth, it seems designed to be left mostly in place as a display piece of art. Also, the amount of detail, number of rooms, and unusual floor plan as well as its sheer size alone make this piece more compelling than the average "fairy house" or "miniature house" made by craftsmen (I've been involved in miniatures off and on for many years so I've seen a lot of those). I subsequently learned that the Fairy Castle was featured at the opening of the Visionary Art Museum.
More pictures of the castle, including closeups of the rooms, are here.
Artist Debbie Schramer describes how she and her husband first built and exhibited the Castle. Click and scroll down.