Locked chest

Locked Chests (also known as Steve Co. Suppy Crate) have been added with Minecraft Beta 1.4. Clicking on the chest will bring you in the screen shown on the bottom. Clicking on "Go to Store" will forward you to the Minecraft Store. The chests emit light at level 15 and are indestructible by hand or with a tool, but can be destroyed with 1 piece of TNT, see how it looks like here. They may be an April Fools Day joke. The Locked Chest in "Action"

Trivia

 * Locked chests are a pun of the Mann Co. Supply Crates from Team Fortress 2, where a key must be purchased for $2.49 in the in-game shop called Mann Co. Store in order to open the crate.
 * Locked chests are indestructible by hand, but can be destroyed with one piece of TNT

History

 * Locked Chests were introduced in Beta 1.4.