Immense Bright Blue Flash over Cadiz.It was around 23:30, Me and another person were sitting on the roof, All of a sudden there was an immense bright white flash, fading to blue around the edge. It seemed to spread from a disc almost directly above, into shapes like small pools of water. It wasn't symmetrical shape. It illuminated the area around us. There was no noise, and no electrical disturbances.I am a Graphic Designer and Photographer, and have worked in many places over the years. The other witness is a an Accountant, who wishes to remain anonymous. Neither of us drink or use drugs.((NUFORC Note: Witness indicates that date of incident is approximate. PD))