After not playing WoW for several months I've read several posts showing the OHF spot to break through the western invisible wall, so you can explore the isle and the fields and felt the urge to explore some things in there.
I've seen neither of the 2 spots I'm showing in here yet, but if it IS a repost don't hesitate to tell me.
My fraps is broken right now, so just deal with the wall of pics
There are 2 spots to break through the invisible walls:
Spot 1 gets you to Alterac, a small part of WPL, Tirisfal and Old Dalaran. Spot 2 leads to Arathi Highlands.
Spot 1:
Get to the river that usually leads to WPL and walk it up north until you get to this wall:
Get to the left mountain side and walk it up like shown in the next pic:
You should now be in this spot:
Face slightly towards the wall and jump with your mount so you're landing here:
Take a step forward, dismount and hop onto the edge between the wall and the pillar:
Simply jump along the pillar so you get across it. On the other side jump into the river and walk along it until you hit the invisible wall. Dive down as far as you can get and use auto unstuck:
If you get past the wall follow the river north until you can get up a path to the west, following it up you get to the road between Alterac and WPL:
If you follow it north (1), there's the alliance camp and uther's place.
Following the road to the west, you get into Alterac:
Follow the arrow till you get down to the lake without water in it (flying fishies!)
A tad bit to the south, there's the place where Dalaran used to be
If you head to the west, you'll get to a small part of Tirisfal.
Spot 2:
Head to the south-eastern edge of Hillsbrad and swim around that mountain:
You'll hit an invisible wall, dive down to the ground and use auto unstuck again.
Past the wall get a certain distance between you and the wall, you can get stuck in the shown area:
Swim all the way along the coast of Arathi:
Jump up this spot and make your way up:
Just get to the cave and walk through:
Whoop! You are in Instanced Arathi!
Aerie Peak (3.3 PTR only):
Use the spot to get into Arathi and wallclimb (levitate needed) your way up the northern border:
Get up this tiny bit:
Once up use levi/slowfall/iceblock/godshield/whatever to get down there
Extra pic (You can walk outside the border):
Another 3.3-only:
Get north of durnholde and climb up the mountain: