My butt. I slipped while attempting a tic tac (It had just gotten done raining). It's healing, though, as well as my thighs, which were sore from the fall, and my arm which had been cut jumping off a shed. So I haven't been training to hard, not wanting to cause permanent damage.
Also, I'll train smart. I will in the place were I train for 2-3 hours, still, but if I began to hurt I'll calm down on what I do, and just plan things out for when I'm feeling better.