The Guadalquivir River is the second longest river in Spain. The first anchorage grounds were established by the Phoenicians for the precious metal trade. Romans and Arabs continued to use Córdoba as an important river port.
After the discovery of the Americas, the Spanish Empire shifted its international trading port to Seville. Today, the Guadalquivir River is navigable from the Gulf of Cádiz to Seville but no longer to Córdoba.
The Roman Bridge, originally built in the early 1st century BC, has been reconstructed a number of times.
The waterwheel, no longer functioning, has Roman origin. It provided water for the nearby Alcázar gardens and was used to mill flour.
As a footnote, the Roman Bridge was featured in Season 5 of Game of Thrones, as the Long Bridge of Volantis.
It took me a mere 6 minutes speed walking to cross the Roman Bridge from the historic centre of Córdoba. The water level of the river is alarmingly low. It saddens me to ponder how long until the river runs dry.
Aloha -- Cathi