Shrine of the Uberfish
When Tyrande Whisperwind was in the Barrow Deeps to free Illidan Stormrage she saw an opening behind some trees. She went in and walked around a gate to get to a way gate. She went through the gate to find the in-game secret of the Shrine of the Uberfish. Inside was a Mantle of Intelligence +3 that gave a bonus to intelligence when worn.