aperiodic

A Penrose tiling is an aperiodic tiling consisting of only two tiles and containing five-fold symmetry. The wikipedia entry for Penrose tilings has good images and information about it, plus a couple of photos that help you see how the pattern might look when colored in.

I am aware of the existence of a few small Penrose quilts, but from examining the photos it looks like they contain at most three iterations of the tiling. Not surprising — it's hard to find images to work from that have more than three iterations. I had to install Inkscape and use the instructions on this page to render out seven iterations of the pattern, but it's in readiness for when I decide to tackle the pattern.