Were you looking for the Molten Front subzone called The Furnace?

The Furnace is an area of Upper Blackrock Spire. Is is accessed from the hallways beyond the Blackrock Stadium, opposite the entrance to Blackwing Lair. The Furnace holds several groups of orcs and dragonspawn, but its most significant occupant is the Beast, a core hound used as a pet by General Drakkisath, who can be found in the Spire Throne just across a bridge.