We hate motorways, although they offer a safe transit from the cold north, across a snow-laden mesata, to the warm south in Winter.
We have done Bilbao-Marbella 6 times, going different routes each time.
1) (Jan): Burgos, Madrid, Jaen (hotel); Granada, Marbella.
2) (Apr - Palm Sunday very interesting): Malaga, Cordoba, Merida, Cacares, Trujilo (hotel); Montfrague National Park (worthwhile), Plasencia, Salamanca, Leon, Ovido (super drive through tunnels in Picos)
3) (Apr)
onestia, Pamplona, Zaragoza (friend); Teruel, Valencia, Denia (hotel); Alicante, Murcia, Guadix (troglodytes), Granada, Malaga
4) (July): Osuna, Ecija, Hornachuelos, Almaden (hotel); Talavera de la Reina, Avila, Valladolid (hotel); Aguilar de Campoo, Torrelavega.
All done by car, as you might guess from the hotels. Number 4 was through rural Spain for much of the way: no problems. My favourite viewpoint is between T de la R and Avila, at La Parada del Arriero.
5) (Apr): Logrono, Soria, Medinaceli (hill top aire); Almadrones, Quenca (lovely views overlooking city BUT obey all traffic lights!), Castillo de Garcimunoz (quiet aire by castle); La Roda, Albecete, Chinchilla ce Monte Aragon (excellent aire); Hellin, Murcia (excellent aire at IKEA with trams into city).
We then pootled around the coast.
6) (Apr): Torre del Mar, Ventas de Zafarraya (wonderful climb), Alhama de Granada, Montefrio (excellent climb, lovely church, bloody awful streets), Priego de Cordoba (OK aire, free ehu); Cordoba, Penarroya-Pueblonuevo (didn't fancy road to aire), Orellana la Vieja (quiet aire beside sports hall, view over fields); Oropesa (can't remember the route); Avila (past "our" viewpoint again), Coca (fabulous castle), Cuellar (fiesta so roads blocked and aire full of cars), Penafiel (only campsite on our trip; narrow castle overlooking interesting town square used as bullring); Torquemada (aire by church); Castrojeriz, Herrara de Pisuerga (Canal de Castilla: smelly but impressive, not for boats!), Aguilar de Campoo (care with low bridge near aire; alternative aire near lake), Cabarceno (the obligatory aire by the zoo for anyone travelling via Santander); Noja (wonderful spiky rocks in the sea), Lanestosa (didn't like entrance to aire), Espinosa De Los Monteros (quiet aire by river); Bilbao.
Nothing caused us any problems (apart from the little things mentioned) although there were a couple of "off tarmac" adventures but they just add to the excitement of foreign travel.
Obviously me answers don't provide routes directly to SW Spain but they can be taken into account, I hope.
Seville is an interesting city but we needed a satnav to get back to our hotel on foot AND definitely to drive through in a car.
Cadiz is another interesting place but my wife was very upset by the number of feral cats. Walking is the only way to get around in the old centre.
Tarifa is one of the windiest places in Europe, so a mecca for windsurfers.
Barbate has an anchor graveyard: interesting!
I found Cape Trafalgar boring.
Gordon
It depends when you go and what you enjoy. Have a good trip.
