unable to find the class set dungeon at the slayer level. Portal should be at the southern battlements. can not find need help last item at slayer level
It would be extremely helpful if you told us, what class set you’re talking about. 
6 piece set challenge Delsere’s
When you enter Skycrown Battlements, you basically run straight along that bottom edge until you get to the corner at the end and it’s right there.
See this video for the location: Diablo 3: Set Dungeon - Delsere's Magnum Opus (Mastery | How To | Patch 2.4) - YouTube
thankyou for the quick reply