The trees! NOT the well-known one in the main courtyard, but the two trees by the duel lifts. It's fairly easy to hop into the one closest to the platform (hint: Look down and hit the leaves DEAD CENTER) then pull back a bit to get behind the leaves.
Huge surprise element with this spot. Between the shadows and the leaves, you cannot be seen easily from any direction, and with a working motion sensor, you can sit and let the 'buffalo' wander by, ready to be slaughtered. You can wait for someone to run by you on the platform you were just on, jumping up behind them for an easy assassination. You can jump 'ahead' and land on the platform by the (facing) left lift, or (and this is my favorite) you get the sword as a secondary weapon and drop down onto people like Dracula. A quick jump back onto the lift and you're reset for the next victim(s). Very useful with dueling opponents under you.
This spot is killer, pun intended, during a SWAT match. With a BR, you should get at least three to five kills before anyone figures out where they're getting pegged from.