I found a nice little spot to hide the flag. Although casters can still reach you, you'd be surprised just how many people leap off the cliff to their death trying to get to you. Screenshots are as follows:
The way I got down there was simply by positioning myself at the top of the little indentation to the cliff above me, jumping straight up and then tapping my 's' (back) key just as I was about to hit the ground again. I did this until I arrived at the little ledge I'm standing on.
EDIT: In before LOL U GOT 3-CAPPED