In the Gennadius Library of the American School of Classical Studies at Athens, Greece, is a heretofore unknown large-format volume that contains many extra illustrations, original drawings, and proofs of plates for The Arabian Antiquities of Spain by James Cavanah Murphy (1760–1814). Based on research conducted between 1802 and 1809, The Arabian Antiquities of Spain features engravings of major monuments of Hispano-Islamic architecture, including the Alhambra, the Great Mosque at Cordoba, and the Generalife at Granada; the work was published posthumously in 1816. Since the Gennadius volume also includes sketches of Islamic monuments from Malaga, Seville, and Xeres, it appears that Murphy originally intended to publish a complete survey of Hispano-Islamic monuments in southern Spain. In the Gennadius volume, grangerized drawings are placed opposite published engravings for comparative purposes; the drawings include notes written by Murphy to the engravers, and several are hand-tinted, which reveal Murphy’s interest in polychromy. This article presents the newly discovered drawings in the Gennadius volume, which adds to our understanding of the monuments depicted in the published plates of Arabian Antiquities, and serves to position Murphy’s pioneering efforts in the context of architectural scholarship, chromolithography, and the book trade in the early nineteenth century.