The current bridge connecting the two banks of Vila de Arcos de Valdevez is a 19th century construction, begun in 1876 and completed in 1880, which fully replaced an example of medieval origin. From this primitive construction, there are no architectural elements left, so the knowledge of its original structure is based on a scarce bibliography and on some engravings. The monument was composed of four round arches, supported by strong pegs, without eyelets, and with carvings. There were also two access ramps, which rose from the margins to a flat level. Acronyms are not mentioned in any of the stone elements of the construction, although their existence was almost certain, as is characteristic of known examples of medieval bridges. The entire structure is markedly Romanesque. The period of its construction will be located somewhere between the end of the 12th century and the beginning of the 13th century, since in the Inquirições of 1258 the toponym Arcos is already referenced. The existence of the bridge and its association with the local fair, of significant size and importance in the 15th century, as well as an important road network to and from the exterior, were at the basis of the historical, economic and social development of the town of Arcos.