Authorities on the subject say that the name and position of the third
gate are lost.
Now we contend that the mass of ruins called the Scali Caci are the
remains of the third gate, and that that gate was the Porta Carmenta,
as distinctly stated by Virgil in his description of the meeting of
Æneas and Evander, "without the gates." "Thus, walking on, he spoke,
and showed the gate, _since_ called Carmental by the Roman state; then
stopping, through the narrow gate they pressed" (Virgil, "Æn.,"
viii.). The position corresponds with his description, and is just the
spot where a gate would be required. The remains consist of two
different early periods--immense blocks of soft tufa of the Arcadian
period, and blocks of hard brown tufa of the time of Romulus,
corresponding with the material of which his wall is built.
The Porta Carmenta was to the south, and is thus mentioned by
Propertius (iv. 1):--
"Where rose that house of Remus upon tiers of steps, a single hearth
was once the brothers' modest reign."
We suppose he uses the name of Remus here instead of Romulus on
account of the rhythm.