I’m pretty firmly in the camp which believes that the available evidence readily supports not just the existence of alien (to us) civilizations regularly visiting Earth, and perhaps even living here, perhaps under the oceans. If you look at the cumulative evidence, it is considerable.
And if you look at the radioactive desert in Rajasthan, the claim that it was subjected to a nuclear weapon attack in remote antiquity is sustainable, if not to this point proven.
Here is the first link that comes up: https://www.indiadivine.org/8000-year-old-indian-city-irradiated-by-atomic-blast/
In any event, I was doing my daily work the other day, and the word Jamshid kept popping in my head. Jamshid, Jamshid, Jamshid. Finally I looked it up.
He was a purportedly mythological king mentioned in the Iranian national epic the Shahnama, by Ferdowsi.
The whole thing is an interesting read: https://en.wikipedia.org/wiki/Jamshid
But they describe the creation of a bunker to protect from a “winter”:
Yima [Jamshid] attends with a group of “the best of mortals”, where Ahura Mazda warns him of an upcoming catastrophe: “O fair Yima, son of Vivaŋhat! Upon the material world the evil winters are about to fall, that shall bring the fierce, deadly frost; upon the material world the evil winters are about to fall, that shall make snow-flakes fall thick, even an arədvi deep on the highest tops of mountains.”
The Vedivdad mentions that Ahura Mazda warns Yima that there will come a harsh winter storm followed by melted snow.[8] Ahura Mazda advises Yima to construct a Vara (Avestan: enclosure) in the form of a multi-level cavern, two miles (3 km) long and two miles (3 km) wide. This he is to populate with the fittest of men and women; and with two of every animal, bird and plant; and supply with food and water gathered the previous summer. Yima creates the Vara by crushing the earth with a stamp of his foot, and kneading it into shape as a potter does clay. He creates streets and buildings, and brings nearly two thousand people to live therein. He creates artificial light, and finally seals the Vara with a golden ring.
I’m not going to speculate too hard, but it is interesting. Fodder there for that subset of conspiracy historians dealing with these sorts of things.
I will simply say that sounds like a nuclear bunker, protecting from radioactive fallout, and perhaps a nuclear winter.
It also sounds like the Ark. I won’t attempt to determine here which story is most likely older.
If you look at children, they often tell the truth, but in ways which make it hard for many of us to understand just what they are talking about. There is no reason to think civilizations are not the same.