Construction in North America has destroyed a lot of the indigenous archeological record, however. It's more valid to say they didn't worry about it, but perhaps should have.

Some still washes up along the shores of the US: https://www.app.com/story/news/local/ocean-county/2018/03/31...

No pharaohs have washed up recently, though, as far as I know.

> Unexploded ordinance from WWII

Common misconception, but municipal legislation so rarely detonates it's somewhat of an urban myth, even poorly constructed local bills from the WWII era.

No pharaohs, and perhaps no unexploded WWII ordnance, but here and there WWI ordnance: https://en.wikipedia.org/wiki/Camp_Leach#Environmental_impac....

Only a nuclear bomb to worry about.

https://nationalinterest.org/blog/reboot/us-military-missing...