The Baztandarren Biltzarra is the biggest brotherhood festival celebrated by the residents of the Baztan valley during summer. Elizondo
is the setting for the festivities, which are unquestionably the most representative of the valley; they have been official since 1963. After a religious ceremony, the inhabitants of the 15 villages of the valley
parade around the town's streets on floats.
After the procession, a mutildantza takes place in the Town Hall square to the sound of the txistu (Basque flute); it is an exclusively male dance in which the number of dancers increases as the tune progresses.
The morning is rounded off by a mass lunch in Market Square
. During the day, stalls are set up for exhibiting and selling local craftwork and produce and there are performances by various local bands.