The Squad Nine Training grounds is a large forest thats heavily rigged with traps, trees disguised as dummies, missiles, arrows etc. All there to keep you on you're toes. The training grounds are so well rigged that some of the squad members have suffered injuries but when ever Wakahiru-taicho why she rigged the training grounds, She smiled and replied, "To keep them on their toes."
Since the Training Grounds are build the way they are, very few (besides the captain) have walked out of there unscathed.