Via d*lires and travelizmo, this incredible tent meant to be put in trees. The project is called TreeTents

Dutch designer Dré Wapenaar created this singular construction in 1998 for British activists so they could sleep among the branches of trees they were trying to save. Made of steel, canvas and plywood, a Treetent measures 15 feet high by nearly 9 feet in diameter and is large enough for a family. A Dutch campground now rents the tents. You can see a Treetent at the just–opened show "SAFE: Design Takes On Risk" at the Museum of Modern Art in New York.

Tree-hugger centered design? I am a great fan of this sort of "device". I can fairly imagine this kind of stuff in cities. Wapenaar's work is impressive, his website is great, full of interesting projects about tent: tentprojects. The one on the left reminds me a vehicle in Dragonball Z and the other on the right would perfectly fit in our new office:

But maybe the grand pavilion is the best of those temporary architectures: