Festes de Sant Roc
to
Plaça Nova Plaça Nova, 08002 Barcelona

The Gothic Quarter is home to some of the oldest buildings in Barcelona, and it is also has the oldest annual street celebration in the city: the Festes de Sant Roc started in 1589. Held over five days, the festival offers a full programme of activities and the chance to witness some Catalan traditions, such as the sardana dance and the correfoc (a procession with fireworks). The festivities officially begin on August 11th at 6pm with the Cu-cut dalt del ruc, the traditional inaugural parade through the neighbourhood.
More information here.