Circe drew the robe of hot air closer to her body, since she could not be overtly using her powers she had to maintain a proper body temperature when you positioned yourself fifty miles above the ground—It tends to be cold up here.
This was the only type of outpost she could find where the defenses were not so powerful, thereby making it relatively easy for her to be able to make discrete observations.
She had been observing this Guardsman post of the Boreas Family for weeks which was situated by the side of a mountain, where it had been carved out, brick by brick by mortal hands over a span of millennia. Boreas was certainly fond of gestures like these as most of his temples were created using these methods.