The Alcántara Bridge (also known as Puente Trajan at Alcantara) is a Roman stone arch bridge built over the Tagus River at Alcántara, Spain between 104 and 106 AD by an order of the Roman Emperor Trajan in 98. It bears the inscription Pontem perpetui mansurum in saecula (I have built a bridge which will last forever) on the archway over the central pier.