Kingdom Hearts II Connection Worlds

So, I'm just wondering, how does the Keyblade Graveyard connect with Disney Castle in FM+? Is there something there that just connects the two worlds? I know it's just an extra to fight the Lingering Sentiment, but it just seems strange to me that it's Disney Castle that connects and not some other world like Destiny Islands or Radiant Garden.

 

This is a tricky question. However the only thing I can come up with is that it does kinda makes sense that Disney Castle and the Bad Lands are connected is because Mickey appeared there before in Birth by Sleep. Maybe the Lingering Sentiment found a way to re-open that link because he was looking for someone to help him. (probably Mickey)