How to Keep Villagers in One Area Without Walls
Use Emerald Placement Strategically
Place emerald blocks or emeralds in a circular pattern around the area where you want villagers to stay. Villagers are attracted to emeralds, so they'll naturally gravitate toward and remain near these items.
Create a Contained Zone
Arrange emeralds in a perimeter around your desired area. Villagers will wander within this zone, drawn by the emerald items. This method works well for farms, trading posts, or temporary holding areas where you don't want to build permanent structures.
Refresh the Emerald Circle
As villagers pick up emeralds from the ground, they'll carry them in their inventory. Periodically place new emeralds to maintain the attraction zone and keep villagers from wandering away.
Combine with Structures
For maximum control, combine emerald placement with partial fencing or walls. Use emeralds to keep villagers interested in staying in a specific section, while fences provide backup containment.
Alternative: Hold Emeralds
If you're actively working with villagers (trading, breeding), simply hold an emerald block to keep them nearby and focused on your location.