Minecraft wiki entry for Building_a_metropolis, associated text: Lodestone A place where players can adjust their compasses with a lodestone so they can easily find their way back to the city if they leave. The lodestone can be free to use, or you can have a usage fee. If you are building your city in Nether or End, this building is even more important, because compasses can't work without lodestones in those dimensions. In Nether or End, it might be a good idea to place a lodestone near the return portal.