Past the handgun factory that has become an arts centre, behind the rebuilt station with its shiny statue of the first Basque president, there’s a long blackened tunnel with a padlocked door. Begoña unlocks it and we step inside. It smells of weeds. Eighty years ago this month it would have smelt of fear, as crowds of townsfolk sheltered from one of the most infamous air raids in history. Before Hiroshima or Dresden, and long