Minecraft wiki entry for Door-based_iron_golem_farming, associated text: This design, originally created by JL2579, uses 4 spawning modules, with 2 modules per level, with doors surrounding the modules. This pattern could be repeated to fill a very large area with iron farms. The farm also features a lava system to damage the iron golems so that the piston suffocator works more quickly. Youtuber docm77 made this tutorial for the design.