After fifteen years of near-constant searching, I believe I have finally located it. I found the Dwarven stronghold of Rkundzelft and, of course, its legendary vault!
They said I was foolish. They said there could be no Dwarven treasures remaining, that they had been plundered by bandits or lost to time. They were wrong!
I set out tomorrow. In a week's time, I'll be richer than King Faharajad himself! And everyone who laughed at me will bend over backwards when they see the gold this will earn me.