At Berlin's Michelberger hotel, each of the one hundred rooms has a unique design. The Garden Room, for example, has a plywood house inside of it.
Designed by Sigurd Larsen, the room is separated into two main areas: the plywood house, and the "garden." The two-story playhouse for adults features a kitchenette, sleeping area, toilet, and sauna on the ground level, and an additional sleeping area and hammock on the upper level. Outside in the garden are a rain shower, a sunken bath, a dining area, sitting area, and access to the actual outside— a terrace.
(Image credits: via Dezeen)