This Optical Illusion
If I could give one piece of advice on where NOT to put an optical illusion, it would be a staircase. The black and white pattern of the tiles in this photo makes it look like there’s an extra stair there when in fact, it’s just the landing. The black tiles are supposed to help people not fall down the stairs….

But what do ya know? This last black stripe on the staircase is probably responsible for quite a number of people tripping their way up or down the steps, especially if they’re not really paying attention. And let’s face it, who’s really paying that close of attention while walking up and down the stairs? Oh, that’s right. We are.