If you want a city, then Burgos is nice. When we were last there we stayed at Abba Burgos hotel. It has a paid parking garage and is a five minute walk to the cathedral. Just south of Burgos is Lerma. It’s a smaller town. The Parador (hotel) is in an old palace and has free nearby parking. About 20 miles from it, near Santo Domingo de Silos, is where much of the movie The Good, The Bad, and The Ugly was filmed. If you don’t mind driving to visit really small towns, then you could use Santo Domingo de la Calzada as a base. We stayed at the Parador there. It has paid parking. Just south of it is Ermita de la Ascensión (San Asensio de los Cantos), Ojacastro, and Ezcaray. North of it are Sajazarra, a Roman bridge at Cihuri, Casalarreina, Briones, and San Vicente de la Sonsierra, among other places. All these towns are very small and wouldn’t take long to see. You could also drive over to Logroño and go tapa hopping along Calle del Laurel.