The Mysterious Box is an object seen in one of The Legacy/Classic Update's screenshots of the Community World Beta.
Mystery[]
It is said that Sweetie Belle was originally in there. However, when the box was destroyed, nothing was inside.
Notes[]
The box is extremely large, which could contain some of the tallest statues in the world, and glowstone is inside the walls. This could mean that the box could be entered and something was supposed to be in there.