Originally Posted by CMAW

The north shore of the Ebro river west of Logrono has some great scenery to offer, fantastic villages and fun, low traffic roads (from Fuenmayor to San Fuente and Haro). La Rioja lies on the other side of the river but the Basque wines are just as good. I can recommend a detour in the Sierra de la Demanda between Burgos and Soria as well: remote, forested and mostly mild percentages (unlike some of the climbs in Asturias and Cantabria). There's a great via verde, starting in Arlanzon east of Burgos, that takes you deep into the mountains. Further west, you can look into connecting with the camino primitivo (between Oviedo and Santiago), especially around Lugo, a great provincial town that possesses an intact circuit of Roman city walls, one of the most mind-blowing historic monuments in Spain IMO.
I agree that generally speaking you can't go wrong in this region: stick to the secondary roads and the caminos rurales (gravel mostly) and you'll have a great time.