The Gold Snuff Box is the fifty-sixth treasure that can be found in Uncharted: Drake's Fortune.
The Gold Snuff Box is found in Chapter 16 - The Treasure Vault. To get this one, get to the area where there's a I and VII sign around the rusted iron gate. Go to the part of the railing beside the broken section and press forward+X to climb over and hang on it. Now jump backward to the platform where the snuff box is. If you don't want to die getting off the platform, then do a running jump onto the portruding block which is underneath the part of the railing you originally jumped from.