At the ninth milestone on the road to Palestrina, where the road crosses a small brook, is a magnificent monument of ancient Roman architecture, consisting of an arched viaduct built of peperino and tufa blocks. The length of this viaduct is 105 yards, and the highest of the seven arches about fifty feet. The blocks of stone used are in some cases ten feet in length, and they are firmly fitted together without any kind of cement. This viaduct is now called Ponte di Nono.[146] The ancient roadway of polygonal fragments of basalt still remains, but the parapet on each side has been destroyed.
Gabii.
At a distance of about three miles beyond the Ponte di Nono are the ruins of Gabii on the edge of the lake called Lago di Pantano in the district of Castiglione. Numerous traces of the ancient city are still visible. It occupied a long strip of ground extending from the sepulchral mound on the right of the road near the outlet of the lake to the tower of Castiglione. Nibby thinks that this tower stands on the spot formerly occupied by the citadel of Gabii, the original stronghold founded according to the legend by a colony from Alba. In the year 1792 extensive excavations were made on the site by Prince Marcantonio Borghese at the suggestion of Mr. Hamilton a Scotch painter, and a quantity of sculptures and inscriptions now in the Louvre at Paris were discovered. The principal ruins now remaining are those of the cella of a temple built of the famous lapis Gabinus, and some steps in a semicircular form, probably the remains of a theatre. The temple is generally supposed to have been that of Juno alluded to by Virgil.
The form of this temple was almost identical with that at Aricia. The interior of the cella was twenty-seven feet wide and forty-five feet long. It had columns of the Doric order in front and at the sides, but none at the back. The walls of the chamber at the back were here, as at Aricia, prolonged on each side, so as to close the side porticoes at the back. The surrounding area was about fifty-four feet in breadth at the sides, but in front a space of only eight feet was left open, in consequence of the position of the theatre, which abutted closely upon the temple. On the eastern side of the cella are traces of the rooms where the priests in charge of the temple lived.
The shape of the forum can only be partially made out. From the plan published in the ‘Monumenti Gabinoborghesiani,’ it appears that it was a rectangular quadrilateral space, traversed by the Via Prænestina at the southern end, and that it was surrounded with a portico of Doric columns except at the end along which the Via Prænestina was carried. It was believed at the time when the excavations were made that the Curia and Augusteum could be distinguished among the surrounding buildings, but this seems now to be very doubtful. In the centre stood the statue of Titus Flavius Ælianus, the patron of the borough town. The pedestal of this statue with its inscription was found in situ in 1792.
“The stone of Gabii quarried near the lake and the product of its extinct volcano, is used in many of the Roman buildings and especially in the building called the tabularium at the head of the Forum Romanum. It is a hard species of peperino, of a brownish-grey colour, which when exposed to the air becomes paler than the common peperino of Albano. It resists the action of fire, and is a compound of volcanic ashes mixed with small fragments of black, brown, and reddish lava, scales of mica, and bits of Apennine limestone.”[147]
The city of Gabii lost its independence soon after the beginning of the Republican era of Rome. It was restored as a colony of veterans by Sylla, but sank into obscurity, and became almost proverbial for its desolate condition in the Augustan era. It afterwards recovered its prosperity in some degree by means of the celebrity of its cold baths, and in the time of Hadrian was patronised by the Emperor, who built an aqueduct and a Curia Ælia there. The inscriptions found on the spot belong chiefly to the Antonine era, and the busts of Severus and Geta also found there show that in the first part of the third century Gabii was still a flourishing borough town.
Labicum.
The most conspicuous outlying hill of the volcanic district not far from Gabii is that of La Colonna, about three miles below Rocca Priora. It stands apart from the rest of the range, and is easily seen from Rome. From Strabo’s description of the site of Labicum there can be but little doubt that this hill must be considered to be the place to which he refers in his account of the Via Labicana. “That road,” he says, “begins at the Esquiline Gate, at which the Prænestine Road also leaves the city, and leaving both this latter and the Esquiline plain on the left, proceeds for more than a hundred and twenty stadia (fifteen and a half Roman miles) till it reaches Labicum, an old, dismantled city, lying on a mount. The road leaves it and Tusculum on the right, and ends at the station called ad Pictas, where it joins the Latin Road.” There are no ancient ruins now on the spot. In Strabo’s time it was apparently ruined and deserted, and at an earlier date Cicero says that it was difficult to find any inhabitant to represent Labicum at the Feriæ Latinæ. It seems probable, therefore, that it suffered severely in the civil wars of Sylla and Marius, and did not recover itself until the establishment of an imperial villa there gave it some importance.
Præneste.