PONS FABRICIUS (previously named Pons Judaeorum, Four Heads bridge) between the island and the Campo Marzio bank.
from Rodolfo Lanciani  - pages 30-31:
The island of Esculapio should be already connected to the left bank by a wooden bridge since 192 b.C. (Liv.,XXXV,21,5). A similar structure was supposed to be on the opposite side, in direction of Trastevere and the fortified top of the Gianicolo.
On 62 b.C., L.Fabricio, responsible of the roads (curator viarum), transformed it in a solid stone bridge.
The memorial inscription, engraved on both sides, is followed by the statement of the two consuls on 21 b.C., P.Lepido and M.Lollio, that approved the work as fully satisfactory. These inscriptions indicate us the wisdom of the roman management: the contractors of the bridges construction were guarantors of the solidity of the work for 40 years, and only on 41st they could get back the caution money they paid in advance. The fact that the bridge is still survived is the best evidence of its solidity.
The construction date is confirmed by Dione Cassio (XXXVII,45), while the second inscription probably indicates the makers of a subsequent restoration of the damages due to the river flood on 23 b.C.
The bridge, consisting of two large arches and a small flood hole opened in the central pier, has been preserved nearly integral. A further arch toward the bank has been included in the modern embankment. The nucleus consists of tufa and peperino blocks, while the covering, only partially preserved, is of travertine; its replacement with bricks curtains (probably due to the restoration on 2nd century) is dated 1679, as confirmed by an inscription of Innocenzo XI still preserved at the bridge head on the island side.
During the Middle Ages it was called "pons Judaeorum" when the Jewish community occupied the contiguous areas, known as Ghetto.
It is popularly called "Four Heads bridge" due to the two roman four-faces hermas located at the end of the parapets, probably supports of the bronze balustrades; only two of them are still in their place.
It has been recently restored within the works foreseen in Rome for the 2000 Jubilee.