Today Rome is dreich; uncharacteristically grey, drizzly (grizzly?), and cold. Yesterday, however, was glorious with boundless blue skies. I found myself near Porta Maggiore of which I am inordinately fond, and of which I spoke on episode ten of my podcast (no paywall, here on Spotify, here on Apple) and admired the view from via Germano Sommelier, one of my favourite glimpses of this triumphal arch of Roman engineering.
The Porta Maggiore is a travertine monumentalisation of the part of the double-decker aqueduct which once bridged the ancient vie Labicana (now the Casilina) and Prenestina. These are the channels of the first century Aqua Claudia and Anio Novo, engineered to converge as they emerged from the underground channels meandering through the Alban Hills; piggy-backing on the same set of arches in a glorious exercise in Roman efficiency.
Inscriptions on the travertine arch, later incorporated into the Aurelian Walls, allude to the source of the waters in the Monti Simbruini above Tivoli. From this angle the two limestone specuses through which the spring water once coursed are clearly visible; heroic survivors clinging on while the less fancy brick and tufo which made up the rest of the run have long since suffered the vicissitudes of time. It always strikes me as extremely pleasing, in a meta sort of way, that the springs from whence the waters came were filtered through the travertine Monti Simbruini, only to enter Rome through a man-made iteration of the very same rock.