Download Terrain Slicing Dynamic Loading Kit FREE Unity. 

-Slice Unity Terrain into smaller pieces that can be loaded dynamically at run-time.

-Load terrains or other objects dynamically based on the player’s position or custom specifications.

–Create 2D or 3D endless or non-endless worlds.

-Keep your worlds centred about a fixed point, to avoid floating point errors with large worlds.

-Create and destroy worlds mid-game.