Constantine's Bridge - Credit: Wikimedia Commons
Constantine's Bridge (,The bridge was first mentioned by Sextus Aurelius Victor (c. 320 – c. 390), in Liber de Caesaribus, 41.18, who writes the following: "Pons per Danuvium ductus; castra castellaque pluribus locis commode posita" (A bridge was constructed over the Danube; forts and fortlets were built in numerous proper places) , Konstantinov most; ) was a Roman bridge over the Danube used to reconquer Dacia. It was completed in 328 AD and remained in use for four decades. Read more on Wikipedia
Source: en.wikipedia.org