You've probably seen at least some of these before, but they're fun. All of his art had such mind boggling perspective. Escher pieces If this doesn't mess up your mind, I don't know what will!!! 1. The rod in the middle does not exist. 2. How many, 7 or 10. Count at the top and then at the bottom.. 3. Is the door open to inside or outside? 4. Round or square? 5. How many, 3 or..