One of three vaults that are part of the bur flagging quest. You need to retrieve the Ancient Ring with the description that contains the words: a sword ringed in purple fire, with the flames made of artfully layered amethyst shards. If you pick up the wrong one, there is a 15 minute timer before you can pickup another. The surface portal is tiable/summonable (useful if you are taking several characters or a large group).