Yeah. I wonder how the tilesetters actually did the concrete tile-laying part. There are "quasiperiodic" Penrose tilings that are composed of fairly regular "macroblocks", but this Keskuskatu tiling looks pretty random to me. Did they just have huge printouts of the pattern? Did they develop an intuition of which tile goes where after a while? Were they happy to do something different for a chance, or annoyed by the convoluted task? :D