The vacation in Spain is currently in the plains

Skipping Toledo is a mistake

I did a trip through Spain with friends a few years ago where the first half was Peninsular War focused. We flew into Vittoria, and hired a car. We went to San Sebastian (with a day trip across the border), Burgos (staying nearby in Lerma), then Salamanca, day trip to Ciudad Rodrigo, Merida, with a day trip to Badajoz. After that we left that war behind and went on to Seville and Granada, flying out of Malaga airport. The first half of that trip is what would be relevant to you. In Vittoria, we just caught the war memorial (I think we'd been told that the battlefield is mostly unrecognisable and ended up skipping it). Burgos is a lovely city, but the main Peninsular War site is the citadel which I found interesting but not especially memorable. At Salamanca, though, the whole battlefield is still intact and is really impressive. Ciudad Rodrigo is an easy day-trip from Salamanca and it was great as well. I loved the Roman remains in Merida so much that I skipped the day-trip my friends took from there to Badajoz: they said that the walls were amazing, but the rest of the city was plain and modern. So if you only have a week, I would recommend staying three nights in Salamanca with one trip out to the battlefield and one to Ciudad Rodrigo, and a couple of nights in Merida with an optional day trip to Badajoz. We had originally intended to do the trip the other way, starting at Lisbon and finishing in Bordeaux, but at the time we found there were heavy extra charges for picking up a car hire in one country and dropping it off in another, so we changed the itinerary so that our pick-up and drop-off airports were both in Spain. If those kind of surcharges still apply, I'd recommend flying from Bordeaux to Madrid and doing Salamanca and Merida as a round trip from Madrid.

Definitely stop in http://en.wikipedia.org/wiki/Hondarribia if your travels take you anywhere nearby. The bus system in Spain is pretty great. So, if you don't want to drive and the trains don't fit your needs, look into buses.

That's brilliant, vacapinta. Hadn't thought of driving from Lisbon. And instead of heading north from Merida we could head for Toledo, too...

Barça is possible... but it's a nine hour drive from Bordeaux to there. Bilbao is only 6, but from what I've heard it's not really worth seeing. It doesn't have any Peninsular War sites or Roman ruins of note, but I do want to speak up for Bilbao. Gorgeous, quirky city with really great food and art. It sounds like what you want, though, is Salamanca. Segovia isn't too far from Salamanca, although if you don't rent a car, the bus from one to the other is a little awkward. But I regret every day that I didn't make it to Segovia in the year I lived in Spain.

OK, on further review, flying to Lisbon and driving across the border is prohibitive. $1000+ for a week car hire vs $300 for staying in Spain alone. That has me looking to flying Bordeaux-Madrid and doing a loop.

The national park near torla is spectacular if you want nature and hiking but no ruins unfortunately..... Burgos is also fantastic and is one of my favorite smallish Spanish cities. Madrid is a lovely larger city but I found santiago de compestella more manageable and interesting for walking.

Is Astorga anywhere near your planned cities? It is the North and is the "chocolate city" - i.e. there is chocolate everywhere. I former trade route, it has amazing buildings, beautiful cobble stone streets, and chocolate, chocolate, chocolate!

Check to see if there are any night train rides you can take between destinations. (There's a Madrid-Lisbon one with Renfe!) Great way to combine travel with a good night's sleep.