Moonlight Treasure Achievement in Immortals Fenyx Rising
Open a Night Chest.
How to unlock Moonlight TreasureNight chests, as expected, can only be opened at night. They can still be spotted to mark them on your map like any chest, even during the day. On your map, they'll be a picture of a chest with a blue crescent moon next to them. If you approach them during the day, the chest will be transparent. You'll need to wait until night (which can be done by holding to skip time) and then approach the chest. Multiple enemies will defend the chest. Simply kill them all and open the chest to unlock this achievement.
Night chests, in general, are pretty rare. There are 10 on the entire map. However, if you scan the areas and mark things from the Ascension Points, you will almost assuredly find at least one in your travels. Note that you will need to open all 10 of them for More than Twelve Labours (25G).