https://www.unknowncountry.com/dreamland/linda-moulton-howe-the-alaska-pyramid-is-real , https://www.youtube.com/watch?v=4Eu94J694z4
https://www.earthfiles.com/tag/alaska-pyramid
https://www.earthfiles.com/2020/05/18/updated-part-1-western-electric-engineer-worked-700-feet-underground-at-dark-pyramid-in-alaska
The implications of a massive underground pyramid structure potentially from 10s of thousands, or hundreds of thousands of years ago, would certainly change the perspective of ancient history.
https://www.strangeoutdoors.com/mysterious-stories-blog/alaska-triangle
However, it would be too unsettling for many to consider the possibility of humanity making the climb from the stone age to the space age more than once.
https://www.discovery.com/exploration/Alaska's-Bermuda-Triangle
https://paranormal-intersection.blogspot.com/search?q=Alaska+Triangle
A planet wide catastrophe or a war would cause so much to be destroyed & buried.
https://www.legendsofamerica.com/alaska-triangle
The+Alaska+Pyramid+Mystery if true, could be from an off-world ancient base, or a remnant of a hightech civilization. Either way, there isn't suppose to be any ancient advanced civilization, unless part of history has been lost or suppressed.
https://www.ancient-origins.net/unexplained-phenomena/out-place-artifacts-020544
https://www.ancient-origins.net/unexplained-phenomena/ooparts-found-coal-0010767
https://www.ancient-code.com/five-out-of-place-artifacts-that-challenge-mainstream-history
https://weburbanist.com/2018/09/05/out-of-place-artifacts-the-perpetual-puzzle-of-reverse-engineering-mysterious-objects
https://www.messagetoeagle.com/11-extraordinary-out-of-place-artifacts
https://www.historicmysteries.com/out-of-place-artifact
http://www.ancient-wisdom.com/ooparts.htm
FRINGE was a TV series that hinted of some technology back in very ancient times.
https://en.wikipedia.org/wiki/Mythology_of_Fringe#First_People
https://fringe.fandom.com/wiki/First_People#Assumed_History
A_Canticle_for_Leibowitz was published in 1959. https://en.wikipedia.org/wiki/A_Canticle_for_Leibowitz#Background
If there was a big war in the very distant past, most of the ruins & the tech would have dissolved by now.
If it happens again, then there might be legends of cities with tall buildings, fast trains and faster planes. Weaponry that could wipe out a planet.
https://thebulletin.org/doomsday-clock/current-time ,
https://www.cbc.ca/news/science/2023-doomsday-clock-1.6724181 ,
https://www.theguardian.com/world/2023/jan/24/doomsday-clock-at-record-90-seconds-to-midnight-amid-ukraine-crisis
https://theeventchronicle.com/forbidden-history-artifacts
