Grimrock

Exactly one square behind where you pick up the flame sword on level 6 in the halls of fire there is a hidden button on the wall. Pressing it opens the wall just behind that button. In that 1 square room is another button. when you press it it opens another door somewhere. You can hear it, and it sounds near by, but sear as I might I can never find it. Any ides where this opens?

It opens up a hidden door behind a hidden door ;D

I should have known, always with the hidden doors!

There's another button in that same hallway that opens a door on the same wall as the secret room you found. The button inside the secret room you found opens a door inside that other room. It's very close by, which is why you could hear it but not see it.