Art of M.C. Esher, Page 2

Through studying tile patterns of the Alhambra, a 14th century palace in Granada, Spain, Escher became fascinated with repeating patterns.  Escher's brother, Beer, suggested that he look up articles by Hungarian mathematician George Polya.  Polya had studied 17 kinds of symmetry related to crystals and drew representations of them in the article.  Escher copied the patterns and his artist's eye saw how the patterns could be transformed into shapes of animals and figures (Schattschneider, D., 2004, pp.22-23).