<p>The most ancient and fragile bridge of Rome, the ‘bridge of piles’ (Livy 1.33.6: <i>ponte Sublicio</i>, speaking of the 7th c. B.C.; Festus 374), presents a difficult topographic problem, since it was never substantially built. It stayed mainly as a timber construction on stone pile foundations (Lanciani; Coarelli, <i>LTUR</i>) and so did not survive after the 5th c. A.D. (Richardson; Le Gall 80-82, esp. for ancient literary sources and numismatic evidence). Its exact location is still unknown. It joined the *Forum Bovarium to *Trans Tiberim, possibly providing an important connection with the *Aventine through the *Porta Trigemina, and on the right bank to the slopes of the *Ianiculum as well as directly to the *Via Campana (Le Gall 83 n. 4). Le Gall (82-86) has proposed a well-reasoned location for the bridge, downstream from Pons Aemilius; locating its left-bank head immediately S of the *Round Temple by the Tiber, between the *Cloaca Maxima and the *“Cloaca Circi Maximi”. Coarelli’s topographical studies of the Forum Bovarium follow this placement at least for the left-bank head of the bridge (Coarelli, <i>LTUR</i> 113; id. 1988, 33-34). The location of the Transtiberine bridgehead is more obscure; fragment 27 of the Severan Marble Plan, which depicts the right bank across from Forum Bovarium area, neither represents the bridge nor offers a convenient street for it to join (Rodríguez Almeida, <i>Forma</i> 141).</p>