Wikipedia
Kilometroak (Basque for 'kilometers') is a festival organized every year on the first Sunday of October to reach out to the ikastolas (Basque language schools) in Gipuzkoa, Basque Country, Spain.
Kilometroak consists of walking down a circuit of 5-10 kilometers, one dotted with food stands and entertainment. Participants sometimes represent a certain organization, and the money collected is used to assist the Basque language schools in the province of Gipuzkoa. It also aims at raising Basque culture and language awareness, as well as highlighting community bonds. Each year a different town organizes the event. Parents, teachers and students volunteer and plan ahead to have everything arranged for the day of the festival, and contribute until it is over at dusk.