The Pons Sublicius is the earliest known bridge of ancient Rome, spanning the Tiber River near the Forum Boarium ("cattle forum") downstream from the Tiber Island, near the foot of the Aventine Hill. According to tradition, its construction was ordered by Ancus Marcius around 642 BC, but this date is approximate because there is no ancient record of its construction. Marcius wished to connect the newly fortified Janiculum Hill on the Etruscan side to the rest of Rome, augmenting the ferry that was there. The bridge was part of public works projects that included building a port at Ostia, at the time the location of worked salt deposits.

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