Weeeell, there's only two regions you can reach normally, Kanto and Johto. But since you're at New Bark Town, you can go to a whole separate region by swimming opposite to wherever the ship goes!

[SAIONJI THAT'S A FUCKING LIE AND YOU KNOW IT] Kanto and Johto have beaches and forests too, but that other region has cities of gold and the most beautiful of creatures!