This air raid shelter was one of more than 1300 across the city during the civil war. The narrow and winding tunnels were slowly dug to a total of 200m over two years from March 1937. The half-hour tours (generally in Spanish or Catalan but you can book ahead for English or French) provide some fascinating insight into life in wartime Barcelona. Just being inside here and imagining bombs dropping outside is enough to give you the heebie-jeebies.