The Ponte de Trajano is one of the best-preserved Roman bridges in the Iberian Peninsula, spanning the Tâmega river with sixteen arches. It is the reason Chaves exists: the Romans built a settlement here, Aquae Flaviae, to command this crossing and exploit the hot springs nearby. The bridge is still in use for pedestrian and light traffic today.
Two Roman milestone columns stand on the bridge bearing the original dedication inscriptions to Emperor Trajan and his successor Hadrian. The current bridge deck has been repaved and restored over centuries, but the arches are authentically Roman. Walk to the midpoint at dusk when the light falls across the river and the castle keep rises above the rooftops — it is one of the better views in this corner of Portugal.