Ascending and Descending - M.C. Escher - Chapter 31

I'm going to be completely honest with you, I stared at this painting for at least 15 minutes, trying to find out why the people weren't going anywhere. I finally used logic to figure this one out. If you look at the sets of steps on the upper left and the lower right on the top of the building you can see that they look completely flat. But how Escher tricks our minds is he puts steps there to make it seem like the people are going up or down the flight of stairs. I like this painting a lot because it made me really think and use my brain to figure out how this works. I like the way that this painting is so simple but so complex. Simple because all the painting is is, in essence, a building with stairs on the top. But at the same time it can be so complex because the brain can't comprehend what is going on at the top set of stairs.