History of the Bell in the Depths:

One of the great and mysterious sites in the Moonsea area, the Bell in the Depths, is connected with legendary Northkeep, an island kingdom that was the first great citadel of humankind in these cold lands. Northkeep was a great and magical city, and it was under the protection of these magics that humanity first began to press back the orc hordes and take command of the sea.

The power of Northkeep made it an obvious target for orcs, giants, and other evil races. However, these creatures were not inclined towards sea actions, and Northkeep seemed safe until the day when (according to legend) 40,000 inhuman mages, shamans, witch doctors, and priests of all foul races gathered on the northern shore of the Moonsea and began to chant, bringing the vengeance of their gods down upon the human interlopers. The gods (at least some of them) came and destroyed their priests for disturbing them, but also sank Northkeep beneath the waves.

The upper reaches of Northkeep - its slender, now-broken spires - can be seen beneath the water by boats that sail nearby. This is not attempted often, however, as the region is said to be haunted by the original defenders of Northkeep, seeking company in their watch over the Cold Lands. On fog-ridden nights the bells of the tallest towers, despite being submerged, can be heard as far away as Hillsfar.