We next visit *Trajan’s Arch (Pl. D, 3), the best-known triumphal arch in Algeria, an extremely massive structure, 40 ft. high, much restored in 1900. This was once the W. gate of the inner town (comp. p. [296]). Instead of the usual corner-columns of the earlier triumphal arches, it has on each side four projecting Corinthian columns, whose entablature is relieved with rounded pediments in front of the attica. The two middle columns on the E. side terminate in eagles holding thunderbolts in their talons, instead of in volutes as in the usual capital. Of its three passages, which could be closed by means of portcullises, the central one was for vehicles, the two side-arches for foot-passengers. The square niches over the side-gateways, each crowned with an ædicula, were originally adorned with statues.
We now return to the inner part of the town. Between the first and the second S. side-street of the Decumanus Maximus is the Maison de la Piscina (Pl. D, 3), a large dwelling-house occupying two insulæ, so named from the granite basin in the peristyle, adorned with nine little columns of red marble. The œcus, or festal hall, at the S. end, has a tasteful mosaic pavement.
Between the second and third S. side-streets of the Decumanus Maximus lies the open quadrangle of a Granary (horreum), containing numerous grindstones (pilons à blé; Pl. 7, D 3). The house beyond the third side-street contains a Cellar (hypogæum) resting on pillars and lighted by small windows.
The fourth N. side-street of the Decumanus Maximus, in a line with the Voie de la Curie, leads to the ruins of a Monastery of the Byzantine age, containing a balineum or bathroom. The Basilica (Pl. 2, D, 2) is a complete ruin. To the N.W. of it is the Baptistery (Pl. 1; D, 2), with relics of the font and its colonnade.
The House of Januarius (Pl. 5; D, E 2), to the N.E. of the church, still has its balineum.
Time permitting, we may visit the ruins outside the town.
From the great N. Thermæ (p. [290]) we may walk past the Dépôt des Tapis Indigènes, where the carpets made by the Berbers of the Aurès are sold (adm. free), to other remains of Thermes (Pl. C, 1).
To the S. of this point lies the early-Christian Cathedral (Pl. C, 2), separated by a low hill from the outer Decumanus Maximus. This was a basilica with nave and two aisles, 42 by 18½ yds., with clustered columns and traces of the choirscreen and altar-basement. The sacristies (prothesis and diaconicon), adjoining the raised apse, seem to have been entered from the aisles only.
We next cross the hill and descend to the S.W. to the outer Decumanus Maximus. Here, on the left, quite near the bed of a recently formed torrent, is the Château d’Eau (Pl. B, 3), the remains of an octagonal nymphæum or fountain.