Over the week end I got a free tour to the Stawell gold mines & went down to 250mt but the deepest part is 2.5km with over 130km of tunnels.
They have underground machine work shops, kitchens, food & water & oxygen rescue chambers, some parts are like a shopping center without the shops. I know where I'll be going if a nuke came this way. Amazing technology.
I also got to hold a $850,000 gold bar
but I had to give it back
.