More than a mine
Tour the old Homestake area. There is an open mine you can look at, but the best part is the bus tour through the small town, tour guides giving the entwined history of the town and the company. The bus goes to a very high point above the town where th mine was headquartered.One of the old buildings is still open and you can go in and see the huge equipment used in the mine.
Most of the homes in the town were built by the company, the schools, churches, etc. It seemes as though the town was well taken care during the history of this company.
Afterwards, you can pan for gold if you wish.