Grimrock

Hello my friends,

Does anyone of you managed to open any iron door?
I am on level 6 and none of iron doors opened.
Is there any clue how to understand to open any of these doors? I have found a lots of secrets but iron doors are closed

Every iron door has cool loot behind it, they tend to be one of the trickier puzzles to figure out on each level. You don't need any of the stuff, but it sure is nice! Head back to level 1 and try that one out first, it's pretty easy.
Daniel.