Where are the default (system) wallpaper folders located on OS X? [duplicate]

Possible Duplicate:
Where are Apple's default desktop images stored?

Does anybody know where the folders containing the default (i.e. system) wallpapers are located on OS X Lion? (it may not have changed from previous versions of OS X, so please also tell me if you know where they are on a previous version of OS X). Thanks!

[EDIT:] Indeed, a dupe. What threw me off was that I was looking for "Wallpaper", not "Desktop Pictures". Maybe add a tag synonym [wallpaper] for [desktop], to aid searching people who make the same mistake.

Its on:

/Library/Desktop Pictures/

Notice though this is the system library, not the user library, so its right on the root of the drive and not inside your user folder.

Its hidden by default. Go to terminal and type open /Library to open it.

Hope it helps!

Edit: On Finder, you can hit CMDShiftG and paste the path to go to the folder. (thanks Sjoerd)