Okay, vague lay of the land. Port Nyanzaru sits on the north point of a small peninsula that juts into the (large) Bay of Chult, which itself is on the northern coast of Chult. The bay is guarded to the west by a mountain chain that runs up the west coast of Chult, and some small mining communities pepper the area. Up the east coast of the Bay of Chult there's a military outpost and some small communities around there.
Heading east or south or southwest from the Bay puts one into deep, deep, undead-infested jungle.