The pryamid of Caius Cestus (Gaius Cestius) is an ancient pyramidal funerary monument near the Porta San Paolo in Rome. Gaius was Praetor, Tribune of the plebs, and a member of a college of Roman priests. Ruskin 's reference is to a depiction of it by Claude Lorrain. The monument was also included by Piranesi in his Vedute di Roma, the etching having been excecuted around 1748.