This crazy playground stucture is shaped like something called a "Klein Bottle", a mathematical model with only one surface, and no inside or outside. Designed by artist and architect Vito Acconci, it's going to be coming to a neighbourhood in Miami in 2014.
Acconci was recently named Designer of the Year, and along wtih that title comes the privilege of being commisioned to design a large-scale work. This Klein Bottle play structure, in and on which kids will be able to climb and ostensibly learn about mathematical objects, is Acconci's. In addition to being plain old crazy, the play structure will also be the first area in the Miami Design District that will be dedicated specifically for children. Kind of makes you want to be a kid again, doesn't it? [Dezeen]