Olive Oil is a kingdom resource that you can get when you reach level 40 and open your castle in the Burning Sands kingdom. You can produce Olive Oil in your castle by building Olive groves, which are boosted by the Olive Press. You can also get Olive Oil as plunder when you raid Desert Towers in Burning Sands or from resource villages. The Olive Oil you get in The Burning Sands kingdom can be used in the Burning Sands village and becomes an important ingredient in building new and improved buildings once you reach the Legendary levels (level 70+)