The Guadalquivir and Guadiana are major rivers of the Iberian Pensinsula that flow into the Gulf of Cádiz in the Atlantic Ocean. Between them lies the Costa de La Luz. The Guadalquivir is navigable from its mouth near Cadiz to Seville and borders the Donana National Park. The Guadiana forms part of the border between Spain and Portugal and is navigable to Mértola about 40 miles upstream down to Vila Real de Santo Antonio at the mouth.Guadalquivir
The Guadalquivir is the only navigable river in Spain, and the longest in Andalusia. Currently it is navigable up as far as Seville, but in Roman times it was navigable to Córdoba when it was called Betis. The Guadalquivir is 410 miles (657 km) long and begins at Cañada de las Fuentes in the Cazorla mountain range , passes through Cordoba and Seville and ends at the fishing village of Bonanza, in Sanlúcar de Barrameda, flowing into the Gulf of Cádiz, in the Atlantic Ocean near Cadiz. The marshy lowlands at the river’s end are known as “Las Marismas” bordering the Doñana National Park reserve.
Guadiana
The Guadiana forms part of the border between the Portugal and Spain, flowing generally westward through south-central Spain and then southward through Portugal to the Gulf of Cádiz. It enters the Atlantic Ocean near Vila Real de Santo Antonio on the Algarve. The river is 483 miles (778 km) long but is only navigable to Mértola about 40 miles (60 km) upstream passing through Alcoutim.
Costa de la Luz
Some cruises visit the Costa de la Luz (Coast of Light) in Spain that runs from the Guadiana river that separates Portugal from Spain to the Guadalquivir river in the east – north of Cadiz. Despite not being as scenically dramatic as the coast south of Cadiz, this part of the Atlantic coastline boasts long, unspoilt sandy beaches backed by pine woods and sand dunes and many protected coastal reserves including Donana National Park. The shoreline is punctuated by small fishing ports and modern resorts like Ayamonte, Puerto de Santa Maria and San Lucar de Barrameda.