I'm in Zaragoza for 3 days right now. We're visiting some off the beaten path cities. As well as the can't miss San Sebastian!
Burgos, Zaragoza, Tarragona, and Teruel ( visiting son who is working there for a few weeks).
Zaragoza is very, very interesting. Culturally very different. Did a good walking tour this am. Then we went out on our own. Tomorrow, Palace, Parque and Cathedral.