The Northern Sea extends from Kandarin to past Morytania, stretching across the northern edge of the Wilderness. In the part of the sea north and north-west of Kandarin, there are several islands: The Fremennik Isles, Waterbirth Island, Miscellania and Etceteria, Lunar Isle and Dragontooth Island. Most of these islands can be reached from the Rellekka docks, but Dragontooth Island can only be reached from the Port Phasmatys docks. Mermaids can be found on an island somewhere in the Northern Sea.
How the Northern Sea relates to the Lunar Sea is unknown. Some believe the Lunar Sea is a small portion of the Northern Sea, while others believe they are entirely separate. On the world map, they are obviously connected into a single body of water.