Blackrock Deeps Entrance. Once inside your map changes and you should be able to see the entrance to Blackrock Depths. Another massive case solved just days.

It is accessed by a stair-lined shaft that requires one to swim through an underwater entrance. How to find Blackfathom Deeps location in Vanilla WoW. BRD is currently the largest 5-man instance in the game and is likely to remain so making it a true wonder of the World.
The last part is where I got confused and so did others.
You can find World of Wa. Blackrock Depths is the deepest part of Blackrock Mountain ruled by the Dark Iron dwarves who were led by Emperor Dagran ThaurissanSeveral minions of the Firelord Ragnaros also make their home in these lava-lined depths. Blackrock Depths aka Blackrock Deeps BRD is the deepest part of Blackrock Mountain ruled by the Dark Iron dwarves who are led by Emperor Dagran ThaurissanSeveral minions of the Firelord Ragnaros also make their home in these lava-lined depths. It played a large part in the pre-expansion end-game back when the level cap was 60.