The ancient, weathered Iron Forge is 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 (in the Hall of Thanes). As the dwarves uncover more truths about their ancestry, they will likely find greater uses for the Iron Forge. The titans must have given it to the dwarves for a reason.
The dwarves entered one of the great mountains in Khaz Modan to construct a great forge in honor of Khaz'goroth. This forge survives to this day, although many improvements have been made upon it over the years. The city is still named after this edifice — Ironforge.