Hide end of world

Is there anyway to make it so it does not look like your map just falls or into nothing. I have a terrain and when you reach the end u can tell this is the end of the world i want to hide it so it looks like it goes on.

Usually, games use something high enough to hide the view that player cannot climb, like a mountain, walls etc. A skybox would work as the separation with your terrain is going to be visible.

You can prevent your(s) player(s) from going further a certain border by adding invisible walls (using BoxColliders for example).

If you look at the bootcamp demo, you can see that it uses invisible walls to keep the player contained within an area and then uses a terrain without a collider and some clever illusion tricks to make it look like a large world. I suggest you look at this and play around with it.