This is the statue of Marcus Aurelius now before the Capitol.
Even in Benjamin's time the Campagna was noted for malaria.
Professor Ray Lankester, in a lecture given on Dec. 29, 1903, at the Royal Institution, illustrated changes in the disposition of land and water by pointing to the identical ruined Temple referred to by Benjamin. It now stands high above the sea, and did so in the second and third centuries of the present era, but in the eighth and ninth centuries was so low, owing to the sinking of the land, that the lower parts of its marble pillars stood in the sea, and sea-shells grew in the crevices.
Josippon gives these legends in Book I, chaps. iii and iv, when speaking of Zur, whom he associates with Sorrento. Benjamin had few other sources of information. In the immediate neighbourhood of Pozzuoli is Solfatara, where sulphur is found. A destructive eruption from the crater took place in 1198. Hot springs abound, and the baths at Bagnoli are much frequented to the present day. The underground road is the Piedi grotta of Posilipo, constructed by Augustus.
R. Isaac, the father of R. Judah, must be the "Greek Locust" against whom Ibn Ezra directed his satire when visiting Salerno some twenty years before R. Benjamin. See Graetz, VI, p. 441.