The one that sits on triton ave , is part of a quest you get when you defeat Malistiare. Activating this quest , leads you to a tower in MarleyBone. Originally it was intended that completing this quest would give you the key to celestia. But due to complaints , whines and downright hissyfits , because of the difficulty of this tower , it is no longer required to get to celestia. Hopefully celestia will be out soon , for now , it can be played on the test realm.