As said before in here, Bryan Singer posted a pic on Instagram just to tease the X-Men: Apocalypse movie, a pic depicting an unknown character (most likely Wolverine, given his defying stance) preparing to enter a ship. And quite the ship that is, apparently being massive in size.
If we also consider the fact that the action of the film will take place in the "˜80's, we can also presume some other thing about the said ship. We can say that this kind of technology couldn't exist (not even in the Mutant Cinematic Universe) in that period. So what is that?
Apocalypse's Den
One guess is that the giant spaceship is actually Apocalypse's den, an ancient piece of Celestial (the Celestials were god-like aliens) technology discovered by a young En Sabah Nur and used to enhance his powers. However, as seen in the end-credits scene of X-Men: Days of Future Past, the young Apocalypse already has a colossal power, so we might be a bit mistaken.
Another possibility would be that this ship was found by Apocalypse well after the pyramids were built. In the comics, the ship is actually an A.I. called, well, Ship, and is a piece of Celestial technology overtaken by the mutant. The ship served as his den for many centuries, until X-Factor (another team of mutants) released it and made it their own headquarters.
Expanding the universe
If this is the case, then this is the opportunity for Fox to expand the universe into the outer-space and introduces races such as the Shi'ar Empire. Aliens do not exist, at this moment, in the Mutant Universe. But if that spaceship teased for X-Men: Apocalypse is indeed a piece of Celestial technology then the road is open for the studio to explore new stories set in a much bigger cinematic universe.
Time-traveling
Another possibility would be the time-traveling one, with this already happening (in a way) during Days of Future Past. Apocalypse is known to possess technology which allows him to travel in time.
Is that Wolverine?
Yes, this is a question as big as the one concerning the ship - what is he doing in there? Does he really want to enter all alone? Is this a tease saying that he will eventually become a Horseman of the Apocalypse? 2016 cannot come soon enough to answer all these questions!
