So far no one has figured out a way to leave Belinsk. There is a way to get in. People say that the djinn are no longer there. You can fight Dullahan without all of the djinn. I was missing 7 on my first run through the game.
There is an endless wall glitch to return to vale and you can enter Harappa, exit and die and get the ship back. The glitch is to be on the wall as close as you can get to Apollo Sanctum and still be on the wall. Save and reboot and you should be below the wall. With luck you can reach Vale and other areas. The original glitch topic is said to be on Golden Sun Realm.
There is an endless wall glitch to return to vale and you can enter Harappa, exit and die and get the ship back. The glitch is to be on the wall as close as you can get to Apollo Sanctum and still be on the wall. Save and reboot and you should be below the wall. With luck you can reach Vale and other areas. The original glitch topic is said to be on Golden Sun Realm.