This guide will tell you how to get to Mist Fields (NIFLHEIM BERSERKER GRAVE) in God of War Ragnarok. Go through the guide and follow the simple steps to get it.
The first thing you will need to do is beat the story and talk to the squirrel and he will give you the Yggdrasil Seeds. After that, you will be able to unlock any undiscovered Mystic gateway, then make your way to any Mystic Gateway. Hit the d-pad to undiscovered gateway and hold X to unlock the Gateway. You can use the Mystic Gateway again if you want to get out.