Igulâd Plunge is an Underdark canyon of northeastern Khelan. It is about fifteen miles long widening to a half-mile or so near its center. The bottom of the canyon opens to Nielalroch's undersea. Once leaving the air of the Underdark, swimmers are now 400' under the ocean surface.
When Dushinbal became a sizable city, Igulâd Plunge became the dumping site for their trash and sewage. The sewers leading to this area have a number of bastions built along their five mile length. The defenses are so strong here because Natar's tritons do not like Dushinbal's ideas of waste control.