Minecraft wiki entry for Door-based_iron_golem_farming, associated text: This design is not as efficient as some other designs. However, it is simple to build and lends itself to variation and disguise. The spawning area for the golems is 16x16, but can be made smaller by digging 8 blocks down around the edges if desired. The doors are placed equally around the spawning area, but specific placement can be varied. It is this varied door placement that allows the farm to be easily camouflaged. MCinstructabuilds provides three example disguises, a fort, a town, and a mining camp / Furnace. Unlike other designs the villagers are not kept contained. The Farm can be constructed easily and at ground level.