SONISPHERE FESTIVAL ISTANBUL - Sonisphere Festival Istanbul takes place in July in Istanbul, Turkey. Nothing beats the energy, excitement and variety of a Metallica, Slayer, Megadeth and Anthrax Rock Music Festival! Don’t miss out! Fans who love to hear a variety of musical acts will want to attend Big Four festival. Expect to see a fantastic line-up of top artists. Do not miss this wonderful, must attend event on the annual music festival circuit. The entertainment will be hot, and so will the action. Big Four festival is a top rated music festival taking place in Turkey. Thousands of happy music fans arrive at the event venue to get on with the serious business of non-stop partying and the very best in entertainment. Combine days of concerts with extra-musical activities to add up to a once in a lifetime and one-of-a-kind experience at Sonisphere Festival.