Visit Pamplona During...
July: San Fermín Festival / Running of the Bulls
Technically, San Fermín's saint day is in autumn; however, locals got fed up with the cold and rain hampering their festivities, so they went ahead and moved the festival to July. Irregardless, this week-long, world-famous festival is celebrated for a week each year, with things getting started on July 6th.
Between the "txupinazo" (rockets blasting off announcing the commencement of the festival) and the "pobre de mí" (revelers getting together one last time for the song lamenting the festivities' end), expect 24-hour parties, parades, music groups, markets, fairs and - of course - the daily Running of the Bulls.