Find Marvon Rivetseeker in Tanaris.
I have heard of a place that lies deep below the surface of the earth -- banished there by powers greater than I have ever seen.
If you wish to learn more of this place; the Sunken Temple, seek out a goblin named Marvon Rivetseeker. Much like Troyas and I, he has studied many ancient areas of the world. He was last known to have left his home in Ratchet to study the troll ruins in Tanaris.
Good luck finding him; he hasn't been heard from in some time.