Dragon's Maw

The Dragon’s Maw is an area of the L’Anguille coast a day’s travel from the border with Lyonesse. Dozens of sharp rocks rise from the water, and the tides and currents raise a constant spray from them, so that they look like teeth wreathed in smoke. This is also the area most often hit by storms, with at least one major storm striking every week. Sailors believe entering the area is certain death, but they have no superstitions: the natural features are quite dangerous enough.

However, traders have noticed that people travelling by land within a few miles of the area also disappear. Indeed, no one reliable has seen the area at all for over three years, and those who have gone to look have not come back. The Duke will do nothing, as it is on the coast, and the local lord is (now) a ten year-old boy. He will offer almost anything to adventurers who can bring his father back.

Source

 * Warhammer Fantasy RPG 2nd ED -- Knights of the Grail (pg. 46).