USA, South Dakota, Lead, Homestake Mine

[Frank de Wit]

The former Homestake mine, the biggest and deepest gold mine in North America until its closure in 2002, is set to become one of the largest underground caverns in history and house the largest physics experiment in the study of neutrinos. The site, located under the Black Hills of South Dakota, is expected to host the Deep Underground Neutrino Experiment (DUNE) project being developed within the Sanford Underground Research Facility (SURF) by the US Department of Energy’s Fermi National Accelerator Laboratory.
https://www.mining.com/former-gold-mine-to-host-largest-underground-caverns-in-history/

[Bert de Ruiter]

Homestake Mine / Homestake Visitor Center
http://www.homestakevisitorcenter.com/

Our surface tour of the Homestake Mining Operation takes you through the historic town of Lead and Homestake’s underground surface operation. It follows the mining process including hoisting, crushing and milling of the underground ore and views Homestake Gold Mine’s state-of-the-art Waste Water Treatment Plant and open pit mine. This is a guided tour that takes about 1 hour. You are taken via bus through the city of Lead then up to the Homestake surface operation. You get off the bus 2 times to go inside the different facilities of the operation that are located on the surface. On completion of your tour you will receive a sample of ore that was drilled from the Homestake Gold Mine.

160 West Main Street, Lead, South Dakota, USA

Also see:
https://en.wikipedia.org/wiki/Homestake_Mine_(South_Dakota)
https://www.mindat.org/loc-11872.html