The Uncharted Sea is located in southern Jade Forest.
- This was the name of the seas around Pandaria during the Mists of Pandaria beta, but it was soon changed to the South Seas. Is still appears in the southern portion of the Jade Forest though.
Since it still exists, it might be the large body of water in southern Azeroth, around the southern shores of Pandaria. That area is occupied by the South Seas in-game, but lorewise it shouldn't as the South Seas is part of the Great Sea.