river tiber, tiber island, ponte emilio or pons aemilius on left, ponte palatino behind, rome, italy

ancient arches architecture augustus bridge bricks collapse construction crossing damage embankment emilio engineering floods footbridge forum boarium foundations history infrastructure italy julius caesar lazio masonry medieval piers ponte pons port restoration river tiber riverbank rome roman ruins stone island traffic transport aurelia aemilius palatino 2nd-century-bc oldest single arch mid-river