Claim Gold Mines is the eighth quest of the game and the eigth quest of the main quest series, available as soon as Resource Harvesting is finished.
Click on the [Wilds] button -> Select and assault two Gold Mines. The Gold Mines outside the city have been occupied by opposing forces. Go retake your Gold Mines!
Dinah: Gold is an important resource that our city needs to grow. Let's return to the Wilds and capture our first gold mine!
Hero: I guess you can never have enough gold. Let's go!
After the first gold mine has been captured:
Dinah: Well done, my liege. We have reclaimed the gold mines from the hands of the enemy!
Hero: We mustn't allow them time to recover. Let's go reclaim a second gold mine!
After the second gold mine has been captured:
Hero: Great! I now have control of two gold mines!
Dinah: Congratulations! We now have enough resources to continue developing our infrastructure. Please, head back to the village to continue.