When the main protagonists of the Galactica enter the Tomb of Athena and they apply the Arrow of Apollo by giving it to the archer,
the tomb is shut closed and they appear on a green field surrounded by magical looking obelisks.
There appears to be no door back; after all, they could be anywhere, not really in the Tomb. I was originally thinking they won't ever return to tell the story when I was watching that episode.
They did return though. How did they do it? Did I miss the way out, or was it handwaved?