Minecraft wiki entry for Village, associated text: If a building or pathway generates over open-air, circular or square platforms of grass or sand (depending on the terrain) generates below the structure, which can cause surface oddities. These platforms do not generate beside cliffs or over the void; rather, they generate on the lowest blocks. Platforms can be clearly seen when a village building generates over an ocean. Farms generate a few blocks of open space above them if they happen to generate inside a hill. Village buildings can also generate suddenly on the top of a windswept hills while the other buildings are at the bottom of the windswept hills. This happens often in savanna villages.