In recent years at Reading and Leeds we've seen what used to just be the Lock Up Stage evolve into a three day spree splitting time with 'The Pit' curated by Daniel P. Carter from the Radio 1 Rock Show. The stage has already played host to an impressive set of bands and strong headliners, but none stronger than those just announced.

That's right MASTODON and WHILE SHE SLEEPS have just been announced, and if you were struggling to decide whether to pick up a ticket then we're sure that this might change things.

Mastodon are of course still touring off one of the albums of 2014 in Once More 'Round The Sun and recent live shows dictate that this will be absolutely huge. While She Sleeps are themselves heading full steam towards releasing their new album and much like Mastodon have the capability live of bringing the whole tent down.