The Hilbert Cube: this is a fractal path taking up little space, but with a large length and area. Because the plastic used in printing is flexible, it will stretch out, then collapse to its original form, like a slinky. The Mathematica code was written by George Hart. This will print in white or colored flexible plastic. It is one continuous long unsupported wire, more than 80 inches long, with a 1.5 mm square cross section (it won't print successfully with less)!