These tree house-like cabins by Thai designer Worapong Manupipatpong are built up around the column of a building rather than over the branches of a tree. The three wooden playhouses overlap one another as they stack up around the column and ladders connect each floor to the one above.
The Tiny Tea House is a beauty of a tiny house on wheels with all of the amenities (and then some) needed for small, simply living. More photos and writeup is here. http://tinyhouseblog.com/stick-built/tiny-tea-house