"Designed by architects Steven Holl and Marcela Steinbachová, the library space is completely defined by bookshelves — including shelves that rotate 360 degrees, offering access to even more bookshelves..."
"Doors can be fun. No seriously they really can. The Ping Pong Door functions just like any ordinary door except there’s an inner panel that flips down to make a ping pong table. Pop the little plastic net on and get your paddles ready. The only requirements are the adjacent rooms have enough room for you to play in. The only downside is one side of the door looks normal while the other is bright green. Try fitting that into your home decor."
See more about revolving doors here: