It's like a big magical mailbox funpark with no monitors where you and your friends can send messages and drawings to each other. It's special because you have secret keys to your letters and even if one mailbox doesn't want you to use it, you can always go to another one. No one can take away your drawings, ever! Since it has no monitors, it can be kind of messy right now, but you and your friends are smart and things will get much more fun in due time..