Japanese practice Tezuka Architects aims to tear down the boundaries between internal and external – between built and natural environments – with their project Ring Around a Tree. Staggered floorplates envelope a Japanese Zelkova tree, the stairways and columns dissolving into the shadows of the branches and leaves. It’s a circular piece of treehouse-like architecture designed to be used as a playscape while children wait to go home, and includes non-traditional classrooms for English language classes. The structure is approximately two stories high, but contains six floors for children to run, climb, and crawl across. The platforms are wisely covered in soft rubber mats to cushion the inevitable falls.