West Marches: Westmoor
Entering the palace from the ravine there is a large antechamber. Within the antechamber there is a hole in the ceiling that leads up to the lair of the now deceased Goblin King. Just behind his throne there was a trove of ancient and valuable elven treasure.
If you continue through the antechamber you will come to a spiral staircase the descends into another room below. Nobody knows what lies beyond this door, other than numerous angry goblins.