The Dome of the Eagle (Qubbat Al-Nisr) is considered one of the architectural highlights of the Omayyad Mosque. It was so named because the architect who built it imagined the dome as the head of an eagle, the tracepts as it's body and the aisles at its right and left as its outspread wings. The Arab historian Ibn Jubayr wrote that whoever looks at this dome from a certain distance has the impression of seeing an eagle, whose head is formed by the cupola, its body by the prayer hall, and its wings by the walls on its right and left.
Source: E. Claire Grimes, A guide to Damascus, Avicenne Bookshop, 1997