FERENTINO, the ancient Ferentinum, a town of central Italy, in the province of Rome, is situated on the Neapolitan railway about 45 miles S.E. of Rome. It lies on the side of a hill rising immediately to the left of the Via Latina. It possesses mineral springs, a cathedral, and some interesting remains of the ancient Ferentinum. These consist chiefly of the old walls built somewhat in the cyclopean style, a kind of citadel on the top of the hill, on which the cathedral now stands, and various other portions of old Roman buildings containing numerous inscriptions. The ancient Ferentinum at one time belonged to the Volsci, but soon after the defeat of that people by the Romans in 413 b.c. it was made over with the adjoining territory to the Hernici. It was taken by the Romans in 361 b.c., but so leniently dealt with that, when the Hernici rebelled for the third and last time, Ferentinum was one of the three Hernician cities that refused to join the revolt. In consideration of this the inhabitants were allowed to retain their own laws, which they preferred to the Roman code; but after the social war they accepted the franchise. The population in 1871 was 8360.