Masimong is located in the Free State Province, near the city of Welkom and about 260 kilometres from Johannesburg. The Masimong complex comprises an operating shaft (5 shaft), and a second shaft (4 shaft), which, although closed for mining, is used for ventilation, pumping and as a second outlet. Masimong exploits the Basal Reef and the B Reef. Mining is conducted at a depth of 2 050 metres. Ore mined is processed at the Harmony One plant.

For more information, see the relevant section of the Mineral Resources and Mineral Reserves 2017.