Maurits Cornelis Escher (June 17 1898 – March 27 1972), usually referred to as M. C. Escher, was a Dutch graphic artist. He is known for his often mathematically inspired woodcuts, lithographs and mezzotints. These feature impossible constructions, explorations of infinity, architecture and tessellations.
Relativity, lithograph, 1953. (my personal favorite)
Ascending and Descending, lithograph, 1960
Belvedere, lithograph, 1958.
Drawing Hands, lithograph, 1948.