Not exactly 'Costa del Sol' related but well worth the trip!

"La Tomatina is the world's biggest organised tomato fight. Every year, thousands of people gather in the town of Buñol in Valencia to spend an hour pelting each other with rotten tomatoes.

The tomato fight has become famous the world over, but is actually just one event in a week of festivities that attracts visitors from around the world. This year, La Tomatina will be held on 25 August at 11am"

More info: http://www.latomatina.es/home/inicio/?lang=en_GB