If you look at it from a more biblical perspective you will find life starting in “heaven”, Eden etc
If you consider the mythological perspective then the theme of heaven on earth is also present
Then the eastern angles will tell of the unseen lands that nurture themselves in hidden realms (shambahalla, for example)
Then also if you look at it from a cosmological perspective combined with history (romans)
of course there is always agartha who seem to have started this in reverse (hence their presence in inner earth) and likely started with “war” first and are now enjoying their heaven.
But these are all personal theories and connections from these pointers and maybe a few more, the only one that I know of that is supported by more concrete markers is the age of gold and its research (history, cosmology, mythology) but it’s a very consistent theme.