Minecraft wiki entry for Defeating_the_ender_dragon, associated text: Since the fight takes place in the End, the most important reward is the exit portal, which is the only way back home. It appears all the time, but only activates when the dragon is killed. The portal looks like a fountain made of bedrock, with torches on the sides, and the "water" of the fountain is made of the portal blocks that returns the player back home.