Northern Harbour is the starting area for players with xp level 1. The area starts with large, explanatory arrows and text which introduce the basic funcionality of the game.

If you approach this area from the neighboring area, and find that the gate is closed and blocks your progress, simply go back one area and use the map to get there. You wont be able to use the map to travel there until you've actually visited that area (ie- been stopped by the locked gate).