- This is Giant Mine in the Northwest Territories of Canada.
There are kilometres of tunnels under this rock, and chambers the size of city blocks that have been hollowed out.
In the 20th century, more than 200,000 tonnes of gold were extracted from the rock underneath here.
At current prices, that is somewhere north of US $8 billion worth of gold.
There is a problem, though.
That mining also created more than 200,000 tonnes of toxic arsenic trioxide dust.
That's enough to kill everyone on Earth several times over.
Over the decades, the vast majority of it was stored in the empty, abandoned chambers left behind after mining, although some of it did get out into the environment.
The mine closed in 2004.
When the gold ran out, the mining company went bankrupt and left the mess for the government to clean up.
