You are surprised at how quickly the levitation platform descends into the dark, sulfer-tinged darkness below. The glow of the magical columns casts you and the tunnel walls which rush by you in an eerie, orange glow. As your ears begin to pop, you suddenly emerge from the vertical shaft and enter an enormous underground cavern, lit with the glow of dozens of massive forges in addition to a few everburning torches. Hundreds of small figures scurry around these forges, carrying metalworks in carts, hauling iron ore to the forges, or buckets of water to cool the metal from a large, central well. Others work the metal with large hammers on their anvils, or operate enormous mechanized tools. As you get closer to the floor you can see that most of the workers are human, dwarven, goblinoid and warforged, all seeming to work next to each other with little difficultly. Many are gathered around the central fountain, taking a break and talking with each other, segregated into their various racial groups.
The descent of the cage begins to slow as you reach the bottom, and the operator opens the door, "Well, take care of yourselves. It can get rough down here, especially away from the central caverns and their connecting tunnels."
Dozens of passages break off from this cavern, and the larger ones have rail beds set in them. The rail lines converge on the far side from where you are now standing. Everburning torches are set at steady intervals on the walls of the larger tunnels, and you can see individuals and groups of humanoids pushing rail carts, or riding hand trucks down them.
Remembering the directions in the journal, the dig is located a walk down one of the smaller tunnels, marked with the goblin sigil for water.