Is the human body really almost indestructible?

I don't mean like Superman, but extremely durable. I watched that old doentary thing called Human Body: Pushing the Limits. Also I've looked at some really unimaginable feats. It seems that a completely healthy human body can take far, far worse damage than we actually open ourselves up to. For example, that woman who jumped out of a airliner being bombed fell 33,000 feet or so without a parachute and came away with only minor injuries. Traceurs (parkour practitioners) seem to warp their bodies beyond imagining, such as jumping from 3 stories up without fear. I've heard of children doing unbelievable feats more often, though. For example, I personally jumped off the top of the local play ground when I was five- I fell 15 and a half feet, and didn't get injured at all. I also run much faster than any of my clmates, save a few that are in track (I'm joining next year, but I've raced quite a few of them so I'm fairly confident of this fact). I've heard of people subjecting themselves to unbelievable extremes, and surviving with barely a scratch. Just how durable is the human body? Not counting weak points such as jumping from somewhere and landing with your foot at an angle. I mean, if you landed perfectly with no error and as little joint stress as possible (rolling afterwards, basically) how much can you endure?