There is a fan theory that the Dawn Throne may have once been the remnants of the launch pad for getting Dalamud into orbit.

That said, it is rather strange how little the Calamities come up in Othard. You hear how the Fourth Calamity related to Bozja and Heaven-on-High, but no mention of the Endless Frost or the Great Flood occur at all. Every history in Othard is given such vague timelines you never know how to align it to the Eorzea calendar.