Eagle's Retreat is a term used to describe the nest of an eagle, which is also known as an AERIE. An AERIE is a large nest built on a high place, usually on a cliff or mountain, by birds of prey such as eagles, hawks, and falcons. The term Eagle's Retreat is often used to refer to a place of refuge or safety, as the high location of the nest provides a good vantage point for the eagle to watch for predators.