The Puente Romano spans the Guadalquivir in sixteen stone arches, originally built in the 1st century BC under Augustus and rebuilt many times since — the present structure is largely Moorish. For centuries it was the only bridge across the river here, the southern entry to the city. Walk it at sunset, when the light catches the Mezquita's tower behind you and the Calahorra fortress on the far bank turns gold. The bridge is pedestrianised; there's a statue of San Rafael (the city's patron) halfway across that locals stop to touch for luck.
Roman Bridge
Ancient sixteen-arch bridge across the Guadalquivir