YouTube link.
Similar in principle to the "tile illusion" previously posted at Neatorama, this one was
named after a pattern noticed on the wall of a
café on St Michael's Hill in Bristol, England. This illusion would make a nice tabletop conversation piece if it were commercially available.
Via
Unique Daily.
Try again....
http://maps.google.co.uk/?ie=UTF8&layer=c&cbll=51.456961,-2.597532&panoid=OsQ8ktiSfq11TX20sJASmA&cbp=12,256.68051465171436,,0,4.6489361702127505&ll=51.456948,-2.597537&spn=0,359.963694&z=15&lci=com.youtube.all
http://howd.ie/b62Caf3walL1LlU51oN5c3
There's more about it here, with a picture showing the wall: http://www.michaelbach.de/ot/ang_cafewall/index.html