This photo has been taken in Heureka, the Finnish Science Center in Tikkurila. This sand area was outside and the patterns have been made by a mechanical "sand drawer"-system which drew a circle but the middle point of the circle changed all the time. Difficult to explain as I'm not sure at all how it really worked. Nice patterns it has made, though. The sand was white, actually. This picture has been through some color editing and I do have some other variations of this.