Just a reminder that providing specifics on, sharing links to, or naming websites where ROMs can be accessed is against the rules. If your post has any of this information it will be removed.
Welcome to PokéCommunity! Register now and join one of the best fan communities on the 'net to talk Pokémon and more! We are not affiliated with The Pokémon Company or Nintendo.
That's the edge of the map. You'd need to make a second map and connect it to that map or just expand that map beyond the player's view. You can find the Map Connections in the Debug menu, and it's pretty simple from there.