Like many other people, I have a terrible fear of open, high places like fire-watch towers. I cannot climb those steps, even though I know they are built as safely as another other structure. (I don't consider this fear irrational. Falling from a great height is horrible!)

Even a picture of a person on a dangerous height will cause my internal organs to clench.

Airplanes are no problem, however, because I can't see down to the ground.