Sometimes there are quests that ask you to find the treasure but there is no button that will show you the direction. Here you have to read the clues in the task description that wil lead you to the treasure.

This time, in the desert, the treasure is hidden not behind the stones, as bfore, but under the sand.

Make sure that you are looking in the right direction. The treasure can be not only to the side of the indicated direction but also slightly above or below it. It is also can be hiding behind some trees, grass or some buildings/ruins, so be attentive.