Rare spawning in unreachable area in map

So it's not a bug but don't know where else to post this.
A rare in my map spawned in an enclosed area in a corner of a map. Neither I nor my summons can seem to reach it and my skele mages cannot hit the rare because there are walls preventing them from "seeing" the rare. The only way I seem to be able to deal damage is by using contagion through the walls but it's slow since I'm summoner.
I got a screenshot of the scene if that might help somehow but don't know how to put it in the thread.