I was messing around with walljumping in ZG, and I found this cave. It's located where the cave in Ruins of Zul'Mamwe is on the STV map. If you go into it, it says you're in Ortell's Hideout in Silithus, and a /who will show you in Silithus. Pretty weird. Here's a video showing how to get there, including how to get out of ZG:
http://www.stage6.com/user/Gann1/vid...cave-inside-ZG
I've found some other stuff outside ZG. If you go north and then east along the mountains, there's a really warped version of Deadwind Pass with no Karazhan and a lot of mountains, and if you continue east past that you come to Blasted Lands, and there's a wall blocking off Kazzak's area. You can walljump behind it to find an Altar of Storms that isn't there in the "real" version of Blasted Lands. That's not in the video though, I don't want to spoil all the fun. I suggest checking it out yourself, it's pretty cool.