Maurist Cornelis Escher was a artist very famous. He was from Holland, and he was born in 1898. He did many woodcuts, lithographs, paintings with brilliant images... He could paint many visual effects like depth or volume, and he do imaginary worlds with many optical ilusions and imposible objects. He was like the simetry, and he was an special artist because he didn't have an specific theme to reproduce in his works.
I think Escher was amazing, because he used difficult techniques and mathematics in his works.
I put here some images, but I recommend you to visist this page.