Actually, there are two easy ways to get there. I have good navigation skills but I'll try my best.
You can either start at starboard town. Jump off the big pier and go north west over the big mountain. You should get to an LC repeat. Walk to the swamp repeat nearby.
Start at treehouse. Head west and walk along the cliffs (or swim beside them). You should get to a port town repeat. Go to the swamp repeat nearby.
It really isn't that faraway. It's situated in the first terrain repeat northwest of the main terrain.