THE PORTA CAPENA.
For a long number of years the present Porta S. Sebastiano (Porta Appia) was considered to be the Porta Capena. This error was rectified after the stone which marked the first mile was found (1584) in the Vigna Naro outside the present gate. From it one mile (one thousand paces) was measured backwards, and the result was the discovery of the exact site of the Porta Capena by Mr. J. H. Parker in 1868; but the excavations have been filled in. The remains consist of the sill of the gate, with fragments of the jambs, and the pavement of the Via Appia with the raised footpath on each side of it. The west flanking tower of the gate is under the gardener's cottage. This was reopened in 1877. The gate was crossed by the Aqua Appia (Frontinus), which Juvenal mentions as dripping, and Martial as showering down drops.
The Porta Capena is represented twice in the reliefs of Trajan built on to the Arch of Constantine. In the days of Tullus Hostilius, B.C. 668, Horatius killed his sister outside this gate. "A tomb of squared stone was raised for Horatia, on the spot where she fell" (Livy, i. 26).
We now arrive at the river Almo (Marrana), which flows through