Ancient world geography and points of interest

[KageTokage]

I believe it's mentioned wind-aspected crystals are capable of levitating and thus landscapes like the Sea of Clouds and the Diadem are able to naturally exist in regions with high levels of wind aether.

[Iscah]

Though we still don't know what the floating island chunks are on the map above Garlemald is. Yet instead of the use of primals in stasis its floating just from sheer magics, right?

I don't think it's worth focusing too much on the floating islands. They could be anything from an arbitrary map decoration to a common hazard of free-drifting floating islands that have come loose from the Sea of Clouds. (I'm not really sure how they're supposed to stay neatly arranged in one place if they naturally float and aren't tethered to anything.)

As for Elpis, there's a specific quote on that which I took note of – from the quest Lives Apart:

HERMES
Although we call this structure a beacon due to its form, it's in fact a magical device. By manipulating the balance of elements, it keeps the isle airborne and maintains the climate thereupon.

There might have been a second mention somewhere later, but I got distracted away from checking my notes for it, and now I don't have them on hand.