To find it at its liveliest, come after work and beeline it to the bar. Order a sangria. Then take note: in its former life, the oak-topped bar was actually a wine barrel. In France. So consider its date with your sangria to be a sort of international reunion.
There are lots of authentic cold and warm tapas, like chorizo puffs, baby eels in garlic, stuffed piquillos and larger plates, including duck confit and paella.