This is a little ambush battlemap I am using to do some encounter testing for various systems. The crates on the elevated area to the east provide hiding places to ambush from a prone position with crossbows or magic against characters coming in from the north or south entrances to the cavern. Also there are two little nooks on the west side of the map both north and south where assailants can lie in wait. I might even use the pool of water in the middle as ambush cover for an underwater ambush.
The arrows indicate slopes that characters can charge up to engage the elevated ambushers. I put the arrows on the Gamemaster only layer so I can remove them easily when I need to.