Indeed there is a terrain exploit. The first time, I got stuck in there after the initial spawn (horray for free-for-all kick fest) and got unstuck by walking out backwards. It spits you out behind the castle. I went in it again, intentionally, one additional time to see if it could be consistently recreated (which it can be). It's in the cell with the dirt spilling in (there's 2 spawn points) on the left hand side, closest to the door. You can get stuck in there and the only way to get out is backing up the invisible hill.
Best way to fix bugs is to find out how to recreate them.
Granted, I think that map should go die in a fire, but yeah... If it somehow makes it off the chopping block, at least fix the glitches.
And while we're at it, can we fix being able to melee THROUGH doors? Or stand inside piles of hay and magically be able to see outside and shoot through?
At any rate, yeah.. Mapmaker, if your map doesn't get removed, fix this area :-p