Orti Lucullani. «Plutar. in Lucullo, Varr. nel lib. 1 de re rust.»
The horti Lucullani, laid out by L. Licinius Lucullus about 60 B.C., were on the southern slope of the Pincian, between the modern via del Tritone, the via due Marcelli, and the via di Porta Pinciana. In 46 A.D. they belonged to Valerius Asiaticus, but were coveted by Messalina, who compelled the owner to commit suicide. After that time the gardens belonged to the imperial family. They contained a palace and the usual porticoes, libraries, and similar buildings, of which only the most meagre traces now remain,--some walls and bases of columns in the via Sistina and the via due Macelli, mosaic pavement in the via Gregoriana (No. 46), etc.
Vincenzo Fasolo, "The Campo Marzio of G. B. Piranesi".
relation of past and present site placement
On a specific level, I now know the exact location of the Piazza del Popolo and the Spanish Steps in relation to the Ichnographia. The Piazza del Popolo is not represented in any way at all in the Ichnographia, however the Spanish Steps is where the Horti Lucullani was in ancient times, but where Piranesi places the Horti Luciliani in the Ichnographia. Piranesi designed a huge staircase leading up to the Horti Luciliani and this may be an example of Piranesi's critical commentary on Roman urban design. (reconstruction)
Campo Marzio - new discoveries
...St. Peter's Basilica and Square match exactly the outline of the Porticus Neronianae and the Temple and Area of Mars complex. The piazza of St. Peter's matches the dimensions of the Area Martis, the Temple of Mars fits within the forecourt of St. Peter's, and the nave and transept crossing of the Neronian Porticus falls right in line with the crossing of St. Peter's. ...so exact, and unquestionably deliberate on Piranesi's part. ...firmly locks the analysis of the life and death axes.
The other discovery deals with the horti Luciliani and the horti Lucullani.
Piranesi places the fictitious horti Luciliani where the horti Lucullani ought to be, and places the horti Lucullani at a location further north.
It is the horti Lucullani that Messalena murdered for.
Lucilius is the father of Roman satire. Is there anything satirical in Piranesi's plan of the garden? Perhaps the answer has something to do with a shrine to Minerva being in the center of one of the building complexes--literally "wisdom" (but also "weaving") in the center of a garden of satire. The theater and salons, now make more sense.
satire 1 a : an ancient Roman commentary in verse on some prevailing vise of folly b : a usually topical literay composition holding up human or individual vices, folly, abuses, or shortcomings to censure by means of ridicule, derision, burlesque, irony, or other method sometimes with an intent to bring about c : LAMPOON 2 a : a branch of literature ridiculing vice or folly
censure 1 : a judgement involving condem-nation a : spiritual chastizement by an ecclesiastical agency
wit implies intellectual brilliance and quickness in perception combined with a gift for expressing ideas in an entertaining, often laughter provoking, pointed way, usually connoting the unexpected or apt turn of phrase or idea and often suggesting a certain brittle unfeelingness
satire can apply to any criticism or censure relying on exposure, often by irony and often subtle, of the ridiclous or absurd qualities of something
The notion of Piranesi being satirical himself throughout the Ichnographia is an intriguing idea.
...the various other gardens and buildings that Piranesi places on the same plateau as the horti Lucullani. Some of them, like the horti Narcissi, relate directly to the Messalena story since it is the freedman Narcissus that ultimately kills Messalena. There is also the horti Anteri--Anteros means "an avenger of slighted love," which describes both Messalena and her husband the emperor Claudius, although for different reasons.
...Tafuri could have said so much more about the horti Luciliani.
The Petronia Amnis of the Ichnographia begins in the east and flows along the southern edge of the Hortulorum valley. Its northern bank in the valley contains the Sepulchrum Agrippae and the Sepulchrum Julii Ceasaris et Drusi, while its southern bank is the ridge of the hill on top of which is the Horti Lucullani and some Turres expugnandae (military assult towers). Eventually, the stream skirts the southern portion of the Equiria and the northern flank of the Bustum Augustii. Ultimately, the Petronia Amnis flows into the Tiber.
The Petronia Amnis of the Ichnographia begins in the east within the valley of the Hortulorum, then skirts the northern flank of the Bustum Augustii, and eventually flows into the Tiber. Piranesi dislocates the Petronia Amnis from its original situation to a more northern position.