Belgium, the country where impossible is possible. At least for artist and mathematician Mathieu Hamaekers who constructed the famous Penrose triangle as an optical illusion in Ophoven, Belgium (map).
The Penrose triangle (Tribar) was designed 1934 by swedish artist Oscar Reutersvärd. 1954 the mathematician Roger Penrose (who is 82 now) played a major role for the Tribar becoming popular. The Statue in Ophoven was build in 1997.