Why are ancient buildings, cities and structures usually found buried underground?

Question

Why are ancient buildings, cities and structures usually found buried underground?

In: 62

Answer 1

Burying things often preserves them. If they weren’t buried they wouldn’t be found, because they wouldn’t be hidden, or they wouldn’t exist because the weather would have destroyed them.

Wind is always blowing dirt around and rain is washing dirt around. As it moves is collects in low spots between buildings or whatever. In some places it will eventually bury the whole place. In other places the buildings won’t be buried. They will just be destroyed by centuries of weather or be bulldozed to make something new.