A Late Roman Pointed Arch Bridge (you read right)

[Eleatic Guest]

It is a stone bridge across the "Arapsu river" near its mouth, 5-6 km west of Antalya, at a site possibly identical with ancient Olbia.

Arapsuyu seems to occur as a placename down the coast (west) from Antalya, Stefan: http://itouchmap.com/?c=tu&UF=-735347&UN=-1097560&DG=PPLA And you can see a river there on the satellite view.

False alarm. The bridge is today partly submerged, but it seems clear that the acuteness of the arch is more perceived than real and that the arch is, if at all, only slightly flattened: http://en.wikipedia.org/wiki/Arapsu_Bridge (go to "External links" for more images)