"In 1819, Shelley wrote most of Prometheus Unbound here, and he described the site in his preface: This poem was chiefly written upon the mountainous ruins of the Baths of Caracalla, among the flowery glades and thickets of odoriferous blossoming trees which are extended in ever-winding labyrinths upon its immense platforms and dizzy arches suspended in the air. The bright blue sky of Rome, and the effect of the vigorous awakening spring in that divinest climate, and the new life with which it drenches the spirits even to intoxication, were the inspiration of this drama." (George H. Sullivan: Not Built in a Day: Exploring the Architecture of Rome, 2005).