Quote Originally Posted by PresidentSEARS View Post
If you head back down the tunnel you run into a heavily guarded entrance, I've never been able to find anything on it though. What is it?
I think I know what you are referring to. I think that this was created mainly for gameplay reasons to block the player from progressing in the opposite direction any further; however, the developers may have wished to give that notion of freedom and make the player feel like Midgar was a large, explorable city.