Name of classification/trope of anime with advanced/ancient civilizations


I would like to use "Laputa: Castle in the Sky" as an example, but the
identifying features that I'm particularly interested in identifying are the
ancient, yet advanced technological civilization(s) that left behind the city
itself.

Is there a word or genre specifically describing the ancient yet
technologically advanced civilization trope (specifically those more advanced
than present day civilizations)?




"Precursors" or "forerunners" would be the title given to the
society/societies that came before but they are not titles that would be
classified as a genre. The closest thing to an official genre title that you
would get is, "post-apocalyptic". Post-apocalyptic settings are those that
take place after the end of the world. in certain instances the end of the
world does not mean the end of humanity and so they start the world anew. I
would recommend searching post-apocalyptic animes if reborn society is what
you are into. Attack On Titan, Gargantia on the Verdurous Planet, and Murder
Princess, are all examples of animes with functional societies that speak of
"technology from the old world", even though the ancient technology is
futuristic by comparison to their own. Enjoy

