In the game, if you could get past those guards, then you would go to that area.
I think there are a number of unused gateways that makes sense, but I don't recall them. Like the Battle Arena colosseum linking to the Gateway to Heaven room and the lobby. Area with Seto has a gateway back to the Gi Nattak-boss-fight area of the Cave of the Gi.
Although this one is more interesting because it is less obvious, and an area that is always blocked off.
