When you go to the Castel Keep theres a series of tall rooms full of Hedusa's and Harpies. I've noticed that there are two doors off to the sides of those rooms at the bottom.
I've also noticed that there are cogs on the wall that spin when you hit them.
Dose any one know if theres a certain combination you have to enter by hitting the cogs to open those doors? I'm at 192% completion, and I'd like to open those stupid doors, I've spent around 4 hours trying to figure it out in the game ... it's getting pretty frustrating.
Also, if you know the answer, do you know if the combination is the same in the reverse castle?