The one that looks like a meteor base is actually in
and the third to last one is in the
also
The doors relate to in Arceus 38-27 when it said "...Behind stone doors, four pillars of light bind the New World to a shadow of our own..." I think the four pillars of light represent the Ruby, Sapphire,Emerald, and Amethyst needed to get to Arceus who will open the "x doors" to get two the New World.