That we know off. Can always add another surviving city.
My idea is another one survived. It was small exploration one and it could "land" to collect samples. Its in Osse.
There were 54 total but theres not 54 named and maybe a dozen crash sites known off.
If youre smart you only need to prepare two.
Intelligence and wisdom. Intelligence is best one to target the spells are rare.
Wisdom has the most spells and powerful effects and monster wisdom saves are generally bad.
Yeah even list empires of faerun points out Netheril is fairly well documented. Surviving liches also contribute to Candlekeep.
Its more like Rome but probably better documented. Its not Punt, Akkad, Sea People or Atlantis.
Im leaning towards elements of 3.5 returning.
Overhauled saves would be one of them though. Going in a more 4E/OSR direction though.
In hindsight starting to think 3.5 is a nice median between OSR glass cannon and 4E+ hp bloat.