The Carnival Season in Greece ends with the celebration of Clean Monday which coincides with the beginning of the Greek OrthodoxLent. On that particular day the custom of Alevromoutzouroma (Greek: Αλευρομουτζούρωμα, literally Flour Smudging, or else Flour Wars), takes place in Galaxidi. The origins of the custom are unclear, however it appears in its current form since the mid-19th century.
Around noon, locals and visitors of all ages dressed up in old clothes rendezvous at a predefined location where flour is distributed in large quantities. Various types of coloring is added for effect while people paint their faces with charcoal. Then they march to the harbor which is usually split into a war zone and a neutral zone for the observers and the fight begins. The participants throw each other (and to unsuspected bystanders) colored flour until essentially they run out of supplies. The event often attracts media coverage.
Source: Wikipedia
