With Gilneas having opened up during the Cataclysm, there are only a few places left in Azeroth we haven't explored yet. For example, we know the Zandalari have a massive island home (currently sinking, if Lorewalker Cho is to be believed) but we've never seen it. Likewise, Kul Tiras, the former island nation and home of the Proudmoore family, has been lost for quite some time. After the Cataclysm reshaped the seas and continents of Azeroth, Kul Tiras vanished. Looking at the map above, we can see that where Kul Tiras stood, the submerged Vashj'ir now occupies that position off of Azeroth's coast.
Where did Kul Tiras go? Did it sink? Did it indeed get pushed out into the ocean to be discovered again someday? Is it unmoored in time and space, a new Timeless Isle of sorts? Where do you think Kul Tiras ended up?