Dating back to the 4th century, this aqueduct provided water for the whole city in the past. This stone bridge was originally over a 1000 meters long, spanning the valley between the hills of Istanbul.
The surviving part is a bit shorter, but it is still well-preserved. Nowadays, the Atatürk Bulvarı boulevard passes under the aqueduct.
Wikipedia https://en.wikipedia.org/wiki/Aqueduct_of_Valens
Address 4 Serdab Sokak, Fatih 34083, Turkey
Coordinates 41°0'58.011" N 28°57'19.047" E