A lone, forgotten tower in the mountain range outside Din Guardi.
A Xanthan Orb was locked away in a cave adjacent to the tower by Werdna to keep it from falling into the wrong hands. At some point, thousands of years ago, Werdna returned to the tower and also imprisoned his contract devil, Rebecca, inside a containment circle.
The party found this tower by chance, and made use of what they found within. They took the Xanthan Orb, equipped themselves with gear found on the third floor, freed Werdna's Din Guardi.