Have you ever gone rock climbing (indoors or outdoors)?
I almost killed myself (unintentionally) a couple of years ago while free-climbing in Yellowstone. I lost my balance and the only thing below me was 50 ft of air, jagged rocks and a few inches of water. My brother grabbed me though, he saved my life.
I don't consider man-made wall climbing to be rock climbing. Good practice and exercise, but it is different when you can actually get hurt, and have to climb down if you decide not to go all the way to the top!
This will get covered by the ad for cheapskates.