ACA-F-007066-0000 The Keep on the Leonine walls, once a summer residence of Leo XIII and then an astronomy observatory. Vatican City Credit: Alinari Archives, Florence WARNING: Permission must be required for non editorial use. Please contact Alinari Archives Date of artwork: IX sec. Period and style: Early Middle Ages Location: State of the Vatican City, Leonine Walls Photographer: Alinari, Fratelli Date of photography: 1890 ca. Place of photography: State of the Vatican City, Leonine walls Collection: Alinari Archives-Alinari Archive, Florence Object type: glass plate Photographic technique: N silver gelatin dry negative Dimensioni: 21 X 27 cm Technical info Image sizes (pixel): 1792 X 2424 Image sizes (cm at 300 dpi): 15 X 20 Image sizes (MB): 2.66 Color space: RGB