So, here's the situation:
I took my first trip into the past today. I quit 3 years ago and just got all the expansions, so it was a new thing and I was pretty freaked out. I go through a maw and am unfortunately randomly placed in Sauromugue Champaign. As I'm sure all of you know, you can't get to that maw in the present without going through the banishing gates v.v /sigh
Anyway, long story short, to return to the past I need to go through the banishing gates and such to get to the maw in the present. I wasn't able to activate any other maws in the past. If there's anyone who has also fallen into this trap on Gilgamesh... let me know. I doubt anyone who doesn't have to deal with GC would appreciate us asking them, so we might as well do it together.
One very, very sad Vancar.