Minecraft wiki entry for Defeating_the_ender_dragon, associated text: The easiest way to destroy the crystals is to shoot them with your bow or crossbow. You should move so that you can see it at least partially, aim your shot just above the crystal from your view, and adjust your aim if needed. When destroyed, the crystal generates a massive explosion. If you cannot see the explosion, you you can listen for the explosion sound. You should always shoot the crystals on the shortest towers because they are the easiest to shoot, and if you are using a crossbow you should check how many arrows they have after every shot.