If you’re Horde you’ve most likely seen the ruins I’m talking about. I first noticed them way back in TBC when I took a flight path from Thunder Bluff to somewhere in Desolace. I wondered what they were and if it was possible to get to them. I spent a lot of time trying to find ways to get up there, and I finally found one and went to explore the area with a friend.
I went back there later and made this
Here are the screenshots from the first time we went there.
Some of the ruins. They are still there and you can get there by flying mount.
We thought these ruins were the only thing there, but we went looking what else was up there since we first managed to get up, which was a bit hard.
This is where we got to. At first we had no idea where we were, but then we saw Dire Maul above us.
Syrco Owl 
You flew past these ruins even as Alliance (going to Dustwallow or Tanaris), although I never tried to get to those ones in particular. I was more interested in the ones between Desolace and Ashenvale, along the ocean facing side of Stonetalon. They were an interesting experience to climb to.
I don’t remember any ruins there, but I remember we went climbing up the Stonetalon Mountains and found this troll hut, a goblin shredder and a lumber mill or something, think I got some screenshots of it and will post soon :)
I can’t remember what they used to look like! Were they different before cata? And yes as horde we do see them a lot :)
Not sure, think they’re the same.
I recognise the top two shots but the bottom two look very odd