Piranesi turns to aqueducts in several etchings for this volume of Le Antichità Romane, demonstrating his interest in exploring urban water distribution systems, along with their utility, scale, and design. This image invites viewers to consider relationships of scale and dimension through exaggerated and distorted perspectives: the castellum disappears behind the image frame, creating the illusion that the ruin is too large for the page, and exaggerating, together with the staffage figures, the monumental size of the water basin and its presentation as isolated from urban movement and daily life. Unlike two other etchings that position ruins related to the Castellum of Acqua Claudia within an urban setting (the “Veduta del Monumento del Condotto delle Acque Claudia e Anione Nuovo” and the “Veduta degli Avanzi, o sia del termine degli Archi che conducevano l'Acqua Claudia sull'Aventino”), the above image suggests that the monumental ruin is too large for the page and isolated from urban movement and daily life. 

Further highlighting the castellum’s removal from the urban environment, Piranesi creates the illusion that water cuts through the middle of the frame and spills out from the edge of the image and into its annotations. This detail introduces a trompe l’œil effect that obscures the boundaries between the flat surface of the text and the three-dimensional space of the image. With this interruption of the text, Piranesi experiments with the relationship between visual and textual space, as he does throughout his works. The illusionistic intrusion of water is particularly apt in this volume, whose primary concern is ancient Rome’s water management systems.
Despite the hint that the text of the caption is severed, the majority of the individual terms remain intact in terms of both spelling and punctuation. It is significant then, that the only word in the text that is split is “incavi” (cavity), at the exact location of the visual cavity that is necessary for accommodating the flow of the water. This play on image and text demonstrates Piranesi’s technical ingenuity, in addition to drawing attention to the role of space through, in, and surrounding the castellum.  
 
Perhaps another lens through which to consider this print is the tension between absence and presence: the absence of the urban environment in dialogue with the presence of the Porta Maggiore, or the absence of contemporary utility, alongside the monumental presence of the ruin. Piranesi’s annotations of this print raise questions about utility by noting what architectural elements are missing and no longer present within the ruin, rather than commenting on what is visible.  
 
Piranesi refers to the Castellum as pertaining to the second largest aqueduct in Rome in his comments in the “Spiegazione della Tavola degli Acquedotti” and visually and textually references the water basin in different prints in Volume 1 of the Antichità Romane, pointing to its significant position in Rome’s urban infrastructure. Yet in the above print, Piranesi offers an isolated perspective that visually divorces it from nearly all metropolitan associations. Piranesi emphasizes the beauty of antiquity’s civic architecture by isolating this structure in the artifice of time and space that this image creates. (CBA)