Heights--when I was a punk kid in high school, water towers were my playground...until one of my buddies took a fall. Next time I went up, I froze about half way up and had to be talked down. I have a 30 foot pullup rope on my climber, and only once have I gone to the top, and only because it was dark and I wasn't looking down. Come sunup, I about soiled my drawers. I will say this--if you are 30 feet up you can see a ways.