Despite the recent info pointing out that Metallica's Orion Fest is scheduled by contract to take place at Detroit's Belle Isle for at least two more years, the latest statement from festival promoters C3 confirmed that the event will take a year off due to metal giants' European concert dates. As Detroit News reports, Orion might return in 2015, but it's still uncertain whether it will once again be held in Detroit. The same source indicates that despite the contract, C3 had the option to back out at any point. During this year's event, Metallica noted they were looking to give Orion a permanent place of residence. "I don't know about you motherf--kers, but I think Detroit should be our permanent f--king home! We love Detroit and we love Michigan!" drummer Lars Ulrich shouted at festival closing. Whether or not the four-piece will return to Belle Isle yet remains to be seen. In related news, Sonisphere festival is confirmed to be making a major comeback, as the 2014 event edition is officially scheduled to take place at Knebworth after a two-year hiatus. Marking the jolly occasion, Metallica and Iron Maiden, possibly the two single greatest metal bands of all time, were announced as headliners. Both acts confirmed exclusive performances for Sonisphere, with Metallica once again announcing their "by request" show, giving ticket holders a chance to shape the concert's setlist through online voting. After describing the opportunity to co-headline the 40th anniversary of Knebworth event as "truly a mindf--k," Ulrich added: "And what could be more fitting on our third Knebworth go-around than to play an all-request set, chosen entirely by the fans?" Finally, Metallica has announced additional European summer dates, confirming June 9 performance at Pinkpop Festival in Netherlands and July 3 show at Rock Werchter in Belgium. Check out the full tour itinerary on the official website.