Revellers celebrate mass before the Batalla de Vino (Wine Battle) in Haro, northern Spain June 29, 2015. Every year thousands of people celebrate the day of the patron saint of the town, San Pedro, with a trek to the mountainous crags of Bilibio. Following a mass in honour of the fifth century hermit, St Felices de Bilibio, a giant battle ensues with participants using any method available to soak each other with cheap wine. The tradition appears to have come about after various participants, following a night of drinking, thought it amusing to stain their white festival costumes with red wine, according to early newspaper reports. (Photo by Vincent West/Reuters)

A man pours red wine on a girl's head during the Batalla del Vino (Battle of Wine) in Haro, on June 29, 2015. Every year thousands of locals and tourists climb a mountain in the northern Spanish province of La Rioja to celebrate St. Peter's day covering each other in red wine while tanker trucks filled with wine distribute the alcoholic beverage to water pistols, back mounted spraying devices, buckets which are randomly poured on heads and into any other available container. More than nine thousand people threw around 130,000 litres of wine during this year's Haro Wine Festival, according to local media. (Photo by Cesar Manso/AFP Photo)

Smoke is seen as revellers dry off with fires following the Batalla de Vino (Wine Battle) in Haro, northern Spain June 29, 2015. (Photo by Vincent West/Reuters)

A young woman is drenched in wine during the Batalla de Vino (Wine Battle) in Haro, northern Spain June 29, 2015. (Photo by Vincent West/Reuters)

A young woman is drenched in wine during the Batalla de Vino (Wine Battle) in Haro, northern Spain June 29, 2015. (Photo by Vincent West/Reuters)

Revellers spray each other with wine during the Batalla de Vino (Wine Battle) in Haro, northern Spain June 29, 2015. (Photo by Vincent West/Reuters)

A woman tips a bucket of wine over a boy during the Batalla de Vino (Wine Battle) in Haro, northern Spain June 29, 2015. (Photo by Vincent West/Reuters)

Revellers dive in the mud during the Batalla de Vino (Wine Battle) in Haro, northern Spain June 29, 2015. (Photo by Vincent West/Reuters)

Revellers dance and cover each other with wine during the Batalla de Vino (Wine Battle) in Haro, northern Spain June 29, 2015. (Photo by Vincent West/Reuters)

A young woman is drenched in wine during the Batalla de Vino (Wine Battle) in Haro, northern Spain June 29, 2015. (Photo by Vincent West/Reuters)

Covered in wine revellers enjoy during the Batalla del Vino (Battle of Wine) in Haro, on June 29, 2015. (Photo by Cesar Manso/AFP Photo)