a town situated at the mouth of the Tiber, about 12 miles to the westward of Rome. It was built by Ancus Martius, the fourth king of Rome, and was called Oflia Tiberina, in the plural number, i.e. the two mouths of the Tiber, which were separated by the Holy Island, an equilateral triangle, whose sides were each of them computed at about two miles. The colony of Oflia was founded immediately beyond the left or southern, and the port immediately beyond the right or northern branch of the river; and the distance between their remains measures something more than two miles on Cingolani's map. In the time of Strabo, the sand and mud deposited by the Tiber had choked the harbour of Oflia; the progress of the same cause has added much to the size of the Holy Island, and gradually left both Oflia and the port at a considerable distance from the shore. The dry channels (fiumi morti), and the large estuaries (Ruggio di Ponente, de Levante), mark the changes of the river, and the efforts of the sea. Its port was one of the most stupendous works of Roman magnificence, and it was a long time one of the best towns on the coast; but having been destroyed by the Saracens, and the harbour choked up, as mentioned above, it has not been able since to recover itself. Though it be an inconsiderable place, and but poorly inhabited by reason of the badness of the air, yet it is the see of a bishop, who is always deacon of the cardinals, and crowns the Pope. The old Oflia, where are seen the ruins of the ancient harbour, is beyond New Oflia, towards the sea; the latter is but a little cluster of houses, with a small castle. It is 12 miles S. W. of Rome. E. Long. 12. 24. N. Lat. 41. 44. There were saltworks in Oflia, called Salina Oflensis, as early as the times of Ancus Martinus (Livy); from which the Via Salaria, which led to the Sabines, took its name, (Varro). It gave name to one of the gates of Rome, which was called Oflensis (Ammian).