Of Old Ironforge, also known as the Hall of Thanes or Assembly of Thanes, the Warcraft RPG lorebooks say:
The Hall of Thanes is a massive, natural cavern complex. It is located in Ironforge’s lowest depths. The area is a true marvel of organic stone formation: no dwarf has touched this area with pick or chisel. Ironforge’s kings are buried in the Hall of Thanes, and the old throne is here as well. Also within this cavernous area is the ancient, weathered Iron Forge â€” perhaps the greatest titan artifact ever unearthed. The dwarves do not use this holy anvil, but keep it near their honored dead and the seat of their power. Brann Bronzebeard believes that as dwarves uncover more truths about their ancestry, they will find greater uses for the Iron Forge. He believes the titans must have given it to them for a reason.
It does exist in modern-day WoW, behind an inaccessible door in Magni’s room - there’s a few ways to get into it, and in the 3.1 PTR it was in fact an openable door (though still blocked by an invisible wall).
However, I’ve never been one to let silly things like walls or door stop me.
Not a lot to look at right now - a long hallway running from the High Seat down to a vast flat stone area (that’s screenshots 1 and 2), then a little winding path that goes under the first area and deadends at two doors that don’t go anywhere. (Oh, and lava. Lots of lava.)
If you liked this little exploration of closed areas, you might want to check out my look at the Farm at the End of the World, and perhaps in a few days I’ll post another good look at the Ironforge Airport. After all, who knows if it’ll still be up there, come Cataclysm?