TYPE Roman Empire, Trajan (98-117 AD), brass sestertius, 23.37g DESCRIPTION . Obv: Laureate head of Trajan to right, Latin legend: IMP CAES NER TRAIAN OPTIMO AVG GER DAC PARTHICO PM TR P COS VI PP around (traces) Rev: Single span bridge with tower on each and boat below, known as the "Danube Bridge", legend: [SPQR OPTIMO PRINCIPI] / S C REFERENCE: SR 1010, RIC 569, Coh 452 GRADING: AF, mostly brassy surface, rare ORDER INFO: R2808, $315 One of the most celebrated architectural ancient coin types. Bridges are quite rare on Roman coinage altogether; this reverse, specific to Trajan, has also an interesting story around it. Traditionally, numismatic literature labels its single-span arched structure with side towers and a variable number of vertical beams (6 in the present case) as the "Danube Bridge", in reference to one of the ancient architectural wonders meticulously described later by Dio Cassius. Commissioned by Trajan as part of his celebrated conquest of Dacia and crafted by master architect Apollodorus of Damascus, it was for more than a millenium the longest bridge of all time, having almost rivalled the "official" world wonders in terms of engineering triumph as well as surrounding mystique. Situated at Danube's treacherous Iron Gate near Kladovo between present-day Serbia and Romania, one may still see traces of some of its 20 pillars that spanned more than a kilometer and were erected in a record two years. Its actual appearance may be gleaned from reliefs on the extant Trajan's Column in Rome, despite continuing scholarly debate as to whether that may not depict a smaller bridge further north in Dacia. Alas, the structure shown here is now thought to represent an altogether different object - the Pons Sublicius, the oldest and most famous of the bridges across the Tiber. Constructed apparently of wood alone and traditionally attributed to Ancus Martius, it survived through successive repaires for almost a millenium, as a witness to virtually all of Rome's ancient history.