Malakoff Diggins

Malakoff Diggins is a square mile open-pit mine, created using an ecologically disastrous method called “hydraulic mining” — basically they’d squirt water against the cliffside, sift through the runoff for gold, and just let the rest wash downstream.

It was closed in 1884 — as a result of the first major environmental law passed in this country, which outlawed the practice — and still looks like a bomb site. It’s a (nearly deserted) state historic park now.