All Catalonia smells of gunpowder and you can hear explosions nonstop. It has started maybe a 20:00 and will not stop till 2:00 or 3:00.
Aside, of course, people drink lots of sparkling wine, eats «coca», dances and, if you are near, party at the beach. Oh, and in ancient times, now it's very hard to get a permission to make one, due to the high risk of forest fires, make a bonfire and jump over it.