History's a lie, nothing is as you're told, but use your eyes and judgment. SEE what is in front of you. All real cultures have stories about a great flood, and a long day or night.
Flood Ruins are discussed occasionally. Sometimes it's call the "mud flood", but that's like the fake flat earth map with "antarctica" in the center. Be wary of controlled opposition. LOOK and LISTEN to who's presenting stuff to you! The messenger is the message!
The ancient buildings, made by giants, which cannot be replicated, are now used as government buildings, the world over. You're not allowed to explore the "extensive sub-basements", and a lot of technology was recovered from these buildings. That's how the Industrial Revolution really happened.
That said, here's a few pictures to get the general idea across.
Is this photo legit? These ancient huge buildings had to be excavated. They do have multi-floor "basements" down there.