The Resident Evil 4 square lock boxes in the Castle section need a special key called a Cubic Device, and you won't be able to open them without it. It's definitely worth doing - those five square ...

While roaming around the Castle, you’ll occasionally come across Square Lock Boxes with very valuable treasures inside. Unfortunately, though, you need a special key to unlock them. In this section of ...

To find the Square Lock Box key, you will need to follow the main story until you reach the Castle Armory. This holds a particularly difficult fight, but afterwards you’ll get the Cubic Device, which ...