Now that we have the area our player will be able to walk through, let's restrict access to that area and minimize the chance of the player realizing it is there.
In order to restrict access to areas, we need to have walls that the player cannot jump over. Now, it would be possible to just create BlockingVolumes, but just having the players stop walking into an area breaks immersion immediately. Having logical reasons as to why a player cannot enter an area is much easier to believe; walls or gates tend to be good ways to do that.
So, with that said, let's build some walls.