starforts

are these like the mud flood where cities were built on top of old cities?

https://www.youtube.com/watch?v=RmwoPF3dyYE

down the street theres a area with a bunch of trees and I was digging and found a old rusty part to a motor or something, I thought it was weird and I remember finding a old wooden wheel in Portland woods as a kid digging. in the future if we get wiped out there will be computer parts and all sorts of stuff underground.