Was playing the Miner quests and one of the NPC was talking about Sil'dih, an ancient city that was much like Ul'dah. She was talking about "gazing upon the ruins" and things like that. As far as I know, that's the only time it's mentioned, and it intrigued me.

I'm really hoping that 2.0 includes actually ruins of Sil'dih. Something reminiscent of the ruins out in Sauromugue Champaign in FFXI, with crumbling walls and towers. Something to liven the area up. Maybe even an explorable dungeon kind of like Shposhae?