PT Alamtri Resources Indonesia Tbk (ADRO), formerly PT Adaro Energy Indonesia Tbk started in 1970 when a Spanish company, Enadimsa, bid for coal concession in Block 8 in Tanjung district, South Kalimantan. The company was named ‘Adaro’ to honor a Spanish family which was involved in mining. Adaro Group mainly runs coal mining operations in South Kalimantan and Central Kalimantan, with 4 billion tons of coal resources and 1 billion tons of coal reserves. The group owns 30 subsidiaries, such as Adaro Mineral, Makmur Sejahtera Wisesa, IndoMet Coal, Kalteng Coal, and Adaro Power. The head office is located on Menara Karya's 23rd floor, Jl. H. R. Rasuna Said Block X-5, Kav. 1-2 Jakarta.