Where did the door in the Chrysalis lead to?

[Enkidoh]

Well, I'm not sure what the Lorebooks said but the ARR artbook interestingly revealed the directive the artist who designed it was given from the writing team stated that the Chrysalis is a pocket dimension made from the "memories of the Ascians", and that the areas that were well defined were meant to represent "where the mind was strong" and "unravelling where the mind was weak" (paraphrased).

And, the whole feel of the Chrysalis matches the 'darkness crystals/platforms' suspended above Etheirys at the end of the Amaurot dungeon much much later in the game (apparently where Zodiark was originally summoned), this kind of makes sense.

So whether that door was based on something from their memories or something else is unclear - it's more likely to be just symbolic and not a literal door, given the Ascians kind of have no need for them (as they simply teleport everywhere, as they're beings of aether and all). Maybe it was meant to represent Zodiark's throne or something, given he's their 'one true god' and all looking at it it does seem to have vaguely Amaurotine icongraphy, so take from that what you will.).