The side quest, On the Wings of Eagles, challenges you with finding an Eagle Egg. This guide on Where To Find The Eagle Egg In NieR Replicant Ver1.22 will tell you where you can find the Eagle Egg so you can collect it, return it, and complete the quest to move onto the next one.
This is one of the many quests you can find in your village inside the tavern. You’ll be sent off exploring to find rare and valuable ingredients and resources, aiding the Tavern Keeper and her patrons. Eventually she will give you the quest On the Wings of Eagles, where she tasks you with finding a rare and valuable Eagle Egg.
Where To Find The Eagle Egg In NieR Replicant Ver1.22
If you speak with the Tavern Keeper after you obtain the quest, she will give you a bit more information. She tells you to explore The Aerie. So head to the Northern Plains and head West to The Aerie. If you consult the quest log you get a few more details telling you to search high places where the wind blows.
As such, you need to head to the exact location shown on the map above. It’s about halfway through The Aerie, near the area with most of the houses in close proximity. Simply collect the Eagle Egg and return to the Tavern Keeper.