I know one that does exist and can be re-opened if they wanted.
Thee largest known deposit of float copper in the world.
Masses that are over 90% pure copper.
Large masses of metallic copper can be difficult to mine, if it is an underground mine. They can be tough even in an open pit.
But mining has become extremely political in the last 50 years.
How much rock/waste would have to be moved per ton of copper is very important.