The Roman antiquities, t. 4, Plate IX. Following the above table. 

This is a detailed architectural drawing by Giovanni Battista Piranesi, an Italian artist known for his etchings of Roman ruins. The drawing depicts the foundation of the Mausoleum of Hadrian, now known as Castel Sant’Angelo. Piranesi’s meticulous attention to detail showcases the complexity of the structure and the incredible skill of the ancient Roman builders. The drawing, part of his multi-volume work "Roman Antiquities," is a valuable resource for historians and architectural enthusiasts.