What have been some of your favorite historic establishments in Spain for food and drink? By "historic" I mean places that have been around since the 1930s or earlier (sometimes MUCH earlier!) Specifically looking at Madrid; Santiago de Compostela; Burgos; Bilbao; San Sebastian; Pamplona; Zaragoza; and Barcelona. Not interested in places that have crossed entirely/solely over to catering to tourists, i.e. riding on the historical cache of something like "Hemingway drank here once" or "Picasso's favorite tapas bar"! Looking for real historic places that continue to cater to locals and visitors alike in authentic spaces and with authentic (and not price-gouged) fare. Any suggestions?
P.S., Feel free to suggest Spain's incredible Paradores, but I almost view them in a separate category. I'm thinking more of places that have always been taverns, cafes, and bars as opposed to places that were once castles, monasteries, and palaces. Thanks!