The Fuji Rock Festival is one of the biggest such events in Japan. Held annually, the festival began in 1997 at a venue near Mount Fuji (hence the name) but typhoon damage forced them to relocate and the festival now takes place at the Naeba ski resort in Niigata prefecture, nowhere near Mount Fuji, though it retains the name.
The 3 day event features Japanese and international artists performing on a total of seven different stages and, in 2005, more than 100,000 people attended the festival. 2006 was even bigger, featuring a diverse line-up that included Franz Ferdinand, the Red Hot Chilli Peppers and the Strokes. The setting is scenic and green, and on-site camping is available for people there for the whole festival (though day tickets are also available). The distance between stages is considerable though, so be sure to pack your walking boots.