Constantine's Bridge (Danube)

Constantine's Bridge (Romanian: Podul lui Constantin cel Mare; Bulgarian: Константинов мост, Konstantinov most) was a Roman bridge over the Danube. It was completed or rebuilt in 328 and remained in use for no more than four decades.^[4] It was officially opened on July 5th, 328 in the presence of the emperor Constantine the Great.^[1] With an overall length of 2437 m, 1137 m of which spanned the Danube's riverbed,^[5] Constantine's Bridge is considered the longest ancient river bridge and one of the longest of all time.^[6]

• http://en.wikipedia.org/wiki/Constantine's Bridge (Danube)