Minecraft wiki entry for Defeating_the_ender_dragon, associated text: While exploring the hallways of the stronghold, a few techniques can be used to help not to get lost. First, notice the placement of oak and iron doors. If the door is flush with the wall, the same way it's facing when you place the door between the walls, it means this doorway leads further from the entrance staircase mentioned above. If the door is carved into the wall, that means the doorway leads toward the entrance staircase. So if you enter the stronghold from somewhere other than the entrance staircase, it is recommended that you trace along the carved-in doors until you find a spiral staircase going upward that is not connected to a room above. This is the entrance staircase of the stronghold, and exploration from this point onward becomes much easier.