Basic production improvement. Requires Mining. * Constructed on: * Hills * Access: * Iron, Coal, Aluminum, and Uranium strategic resources * Gold, Silver, Copper, Gems, and Salt luxury resources * Effect: * +1 Image:20xProduction5.png Production * +1 additional Image:20xFood5.png Food on Salt resource * +1 additional Image:20xProduction5.png Production for Coal, Aluminum, and Uranium. * +1 additional Image:20xProduction5.png Production after researching Chemistry * +1 additional Image:20xProduction5.png Production with Five-Year Plan Order tenet