When are we supposed to stop fighting?

[Theodric]

Despite initial claims that all traces of Ancient cilvilization were likely wiped out on the Source by the calamities, with said calamities seeming to be largely isolated to Eorzea I feel like we're liable to keep stumbling across more as time goes on.

I'm fully expecting those ruins beneath the Bounty that Emet mentioned to be the subject of the EW alliance raids, personally.

Insofar as ruins are concerned, aside from being one of my favourite dungeons in the game I'd note that Skalla is in surprisingly good condition given everything that it endured over the ages.

I wouldn't be at all surprised if it turns out that something similar to Elpis managed to survive even on the Sundered version of Etheirys. I suppose there's also the possibility that at least one of the Reflections evolved in such a way as to discover the ruins of Amaurot and embraced the architecture and teachings of the Ancients.