The journey of the Island
It has taken some time for me to come to this conclusion on what the Island is, but based on what we have seen this season, it has become more and more obvious. Many have said that he Island was Purgatory, Atlantis, etc. which are all very possible.
However, I believe without a doubt that the Island is ship. Not how we think of a ship in the traditional sense but it is a ship non the less. It has a wheel used for steering, it has an energy source used for power, it has some sort of cloaking system to keep it protected.
Why can we unequivocally call it a ship now? Episode 1 of season 6, we seen the Island submerged. This was a big clue – as they are telling us this ship has sunk just like we would see a typical ship sink. The Island ship is a special ship obviously, it possibly can navigate from dimension to dimension, from one time period to another, etc.
Where did it come from? Why does it exist? Who created/owns it? are all major questions that I believe will be answered this season.
I don’t really call this a complete theory, but it can be the start of one. Please add your thoughts.