July 8 2011 - The third Sonisphere music festival officially kicked off in Knebworth today. Fans were treated by performances from "The Big 4" Anthrax, Megadeth, Slayer and Metallica.
It marked the first time they had played together in the United Kingdom. Other performance's include Japanese Voyeurs who opened the Bohemia Stage.
You can see photos from the day one of the festival below and more on Gigwise over the weekend.
For more information about Sonisphere and all this year's summer festivals, check out the Gigwise Festival Guide.
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