Just a bit of pedantry - the story linked (correctly) identifies the Kola superdeep borehole near Pechenga, Russia as the deepest hole humanity has ever drilled, at some 12,200m/40,000ft.

However, 'dug' in my book is not the same as drilling; the deepest hole ever dug (unless you want to go all fundamentalist and claim 'dug' implies shovels and pickaxes and nothing else!) is the Bingham Canyon open-pit mine in Utah, at some 1,200m/4,000ft. (They've been at it for more than 100 years!)

The deepest mine? Mponeng and TauTona, two South African gold mines, at approx. 4,000m/13,000ft. (And counting!)