Trajan's Bridge () is a Roman bridge in the civil parish of Santa Maria Maior, in the municipality of Chaves in the Portuguese northern subregion of Terras de Trás-os-Montes.
History
thumb|235px|left|The view of the bridge and the southern margin
thumb|235px|left|A downstream view of the bridge
thumb|235px|left|The road top of the bridge
thumb|235px|left|Downstream view of the bridge
thumb|235px|left|Upstream view of the bridge
The bridge was constructed at the end of the 1st century or beginning of the 2nd century, by engineers under the emperor Trajan.
The bridge was first depicted in the book of Duarte d'Armas in the 16th century, as seen from the eastern bank, showing 14 arches, interlinked by talhamares with guards, and on the northern bank some watermills. On 7 December 1514, the first foral (charter) was issued by King D. Manuel and included a representation of the bridge in its coat-of-arms.