With a who’s who of rock rolling into Knebworth over the coming days, Sonisphere Festival is set to be a monster.

The three day festival of metal in the grounds of Knebworth House blasts into action tomorrow night (Friday) with four giants of the genre - Metallica, Slayer, Megadeth and Anthrax playing together in the UK for the first time.

Hitchin’s goth rockers My Passion are also playing on Friday night on The Bohemia Stage, along with a much-anticipated Killing Joke set and the fabulous backwater banjo covers band Hayseed Dixie.

Saturday night has a totally different feel with surprise Apollo Stage headliners Scottish pop rockers Biffy Clyro with support from fabulous rock nerds Weezer.

The magnificently spooky The Mars Volta look to be a highlight for the festival headlining the Saturn Stage while earlier Richard Cheese and his Lounge Against The Machine will be putting the Sinatra into Slayer.

Original goth band The Sister of Mercy headline the Bohemia Stage.

The final day on Apollo is going to be LOUD. The stage sees the legendary Motorhead and the hugely powerful Mastodon play one after the other before Limpbizkit and Slipknot finish off the speakers.

Another surprise headliner, comedian Bill Bailey, will close the Saturn Stage, after the marvellous Airbourne, who put in a fantastic performance at last year’s festival, topped by an impromptu screaming guitar solo hanging off a very high bit of scaffolding.

The two main stages, which face one another across the park, alternate, so you won’t miss the big hitters because you are watching someone else, unless you are at one of the smaller stages, or at the fair, or hiding in a bar…

If you haven’t got your tickets yet, weekend camping and day passes are still available “but moving very fast”, the organisers said. VIP, Rock Royalty packages and family camping tickets have sold out.