Plan and elevation of the monument of the Waters and Julia Marcia Tepula Porta St. Lorenzo 

This is a plan and elevation drawing of the monument of the Waters, also known as the Porta St. Lorenzo. The etching, by Giovanni Battista Piranesi, an Italian artist who lived from 1720 to 1778, is a detailed rendering of the ancient Roman aqueduct. Piranesi is known for his detailed engravings and architectural drawings of Roman ruins. The drawing shows the archway, inscription, and surrounding walls of the Porta St. Lorenzo, using a combination of plan and elevation views to capture the structure's form. This engraving reflects Piranesi's interest in classical architecture and his commitment to recording and preserving the ruins of ancient Rome. The work is an important example of Piranesi's contribution to the field of architectural drawing and a valuable document of Roman history and engineering.