Graeme, with a car you have lots of possibilities but if it's Tour time, the roads are going to be, er, busy! Out of high season these roads are largely empty and of great quality, none of your UK potholes but in July and August, particularly the latter, it gets crowded.
But, you're no distance away from the Tourmalet and d'Aspin over which the Tour is almost certainly passing. Until you stand on them you can't believe how steep they are and although you'll see plenty cyclists toiling up on an enormously low 'Granny' gear, the idea of racing up them makes you shudder. 13K uphill without a break.
There's any amount of great walking in that area; you're surrounded by high hills and don't miss the forest walks through the gorges. These are some of the oldest woods in Europe.
Do you have a route in mind between Santander and Luchon? You could go via Pamplona, detour up to the Pass of Roncevalles where battles have been fought that decided the fate of Europe and if you're into bird life it's one of the main migration routes 'tween Europe and Africa. Hemingway country too. He wrote a lot there.
You're no great distance from Gavarnie and its magnificent Cirque. I know Gavarnie comes in for a lot of criticism for its tourist tat and the dung trail but it's still a lovely little place after they've left. They're mostly pilgrims up from Lourdes. Also the good walk up to the Breche.
There aren't that many roads cross the range; the French and Spaniards have never been bosom buddies and most of the roads on both sides end in a valley head or cirque.
Speaking now from personal experience only, the food and drink is better on the Spanish side. The Spanish locals are polite, a little reserved but very friendly. They don't try to cheat you. Their wines are improving, are very reasonably priced, being heavily subsidised but if you're eating in the small mountain towns you'd better not be a vegetarian.These people are serious carnivores. Platters of meat(delicious) that would fill a family; all yours, with perhaps a potato and a stuffed pepper.
I've had less experience on the French side but staying in the only hotel in Lescun was given lousy food for dinner, left over bread for breakfast, bitten by fleas and grossly overcharged.
You'll gather from the above that I've enjoyed my Pyrenean trips. I was fortunate to have friends in Toulouse and made the trip several times.
You'll have a great holiday. It's the most interesting mountain range in Western Europe. You'll also enjoy the ferry; it's a great, if expensive start to the holiday. The food in the dining room is quite good too, certainly on Brittany Ferries.
Oh, and San Sebastian is certainly worth two days.
