Driving in the Pyrenees from Pamplona to St Jean De La Luz

Roncesvalles in the foothills of the Pyrenees, and starting point of the Camino de Santiago de Compostela.
http://www.spain.info/que-quieres/ciudades-pueblos/otros-destinos/orreagaroncesvalles.html

I would go through the Baztan Valley You don't say when you will be there, but now that it seems that the cold weather has gone, any time will be nice. Here is a nice hike, the Xorroxin waterfall. When you come out of the valley into France there are several caves that you can visit. The cave of Urdax has 14,000 year old cave paintings and the cave of Zugarramurdi is where the last witch coven in Spain was rooted out by the Inquisition.

The valley is about 45mins from Pamplona.

Depends which route you’re taking to get there. If you take the route through st Jean Pied De Port, then Roncesvalles is worth a very brief stop. If you wanted to hike a portion of the Camino de Santiago it goes right past Roncesvalles. It’s generally the first night’s stop on the Camino if coming from France. St Jean Pied de Port is worth an hour or so visit since that’s where the Camino in France generally begins. You could also walk a portion of the Camino starting there. If you take the route through San Sebastián, then Hondarribia on the border is worth a few hours. There are a few really small towns along either route, but there is little worth stopping for. Do some research and you’ll probably find something (hiking, parks, river, waterfall, etc.) along the way that you’ll find worthy of a visit. I hate when I return from a trip only to find out I was by an interesting place, but didn’t know it was there.