Where next in Spain?

After a Rick Steves Basque tour, I rented a car in San Sebastián and went west along the coast to Santiago de Compostela with an overnight stop at a Paradore in the Picos de Europa. Then it was on to Madrid, visiting Avila and Segovia on the way. Beautiful sights, wonderful scenery and excellent roads.

If you want to keep your rental car (picked up in Barcelona?), then dropping it anywhere in Spain would be cheaper than dropping over the French or Portuguese border (compare prices). Additional destinations in northern Spain around the Camino de Santiago, Rioja wine region, and Picos de Europe might not offer the same variety as traveling further, but could feel that you'd seen the north well. With your car, you could also cross easily to the French side of the Basque region, but return again to Spain, if car rental savings make it worthwhile.

Biarritz and Bilbao are both international airports, so I think that airline partnerships should allow you to connect from there on one trans-Atlantic ticket.

Like Phillip, I would suggest a journey across the north of Spain, finishing in Santiago de Compostela. There is so much to see along this route that it requires more than just one stop along the way.

Day 1 - To Santander
Day 2 - via Santillana del Mar & Gaudi site at Comillas to Picos de Europa (2)
Day 3 - In Picos de Europa (mountains)
Day 4 - To Leon (nearby is Astorga for Gaudi site)
Day 5 - To Oviedo (historic city)
Day 6 - via Lugo (city walls) or A Coruna (Hercules lighthouse) to Santiago de Compostela (2)
Day 7 - In Santiago de Compostela (pilgrmage site)

I haven't been to Lugo and found Santander OK but not particularly interesting. I'd consider subbing in Burgos, or you could visit some of the many attractive small coastal towns and cities that would be accessible by car, starting from Hondarribia near the French border. Otherwise, I like all of David's suggestions. However, I note that this is a late-March trip, and I am not sure what conditions will be like in the Picos de Europa area at that time of year if you don't ski (I assume there's skiing there). I visited in July and found that one of the public buses ran only from the last week of June through the first week in August. I think that must surely say something about the weather in the area.

To me, northern Spain from the Basque Country westward is an ideal destination for mid-summer travelers because you don't get the extreme heat of central and southern Spain. I'm not convinced that it's the best choice for late March.

My thoughts, the northern coast of Spain isn't ideal in March and the mountains in the north can be freezing then. If you go into France stay on the Atlantic because it's mistral season in Provence (really cold too).

I'd suggest Barcelona as a great stop. That's also the time of year they have the fire festival in Valencia, Las Fallas, so that may be a great addition to your trip. If you are going that direction, not far from Pamplona is a great castle at Olite. It's not huge but it's a great visit - the right balance of restored and ruin so you can explore freely, climb towers, etc.

All of your response have been very helpful....not sure we are over the hump yet though. Cautions about weather have us rethinking (again) a bit.

Since we are starting in Barcelona, what about staying south and doing the Spanish south coast, valencia, granada, malaga, maybe Seville? Warmer, for sure...as interesting?

We were originally following our taste buds and thought San Sebastian and that region would be the gastronomical big time, but maybe we save that for a summer trip some day.

What are you thoughts on this plan?

Thanks again

I am a weather-focused traveler and would definitely head south if I were in your shoes. I haven't been to southern Spain recently, but I hope to return at some point. Others here can give you pointers based on current experience. You can go to skyscanner.com to see what your flight options might be from Barcelona to Andalucía.