The annual celebration festivities Fuegos del Apostol in Santiago de Compostela are usually a week of music, film, fireworks, cultural programmes and other entertainment and attractions.
July 24 and 25 are the main days. Perhaps you saw earlier great presentations on the facade of the cathedral.
In 2015 this wall presentation concentrated on the other side of the Plaza do Obradoiro.
The gothic facade of the cathedral pyrotechnically rebuilded.
For some other multimedia shows of earlier years with spectacular narrative shows on the cathedral see an earlier post on The Pilgrims Gaze.