When anyone first enters the Pyrimo, there is a door to the North and South. The south one is locked for reasons I don't understand, it doesn't lead anywhere you can't get to without going through the North. The only thing it does being locked is annoy Friends who try to go the shorter way to exit the Pyrimo.
Addendum because I'm an idiot.
This appears to be somewhat random due to circumstances I can't explain, sometimes it is locked sometimes it isn't.