Irôchâr Plunge is an Underdark canyon of eastern Khelan. It is about twenty miles long widening to a mile near its center. The bottom of the canyon opens to Nielalroch's undersea. Once leaving the air of the Underdark, swimmers are now 300' under the ocean surface.
Irôchâr Plunge is cut with many switchbacks composed of stairs and paths, rising roughly 400' up from where it meets the ocean. These steps were first cut in the Dawn Era, when Natar was built to serve as an outpost for forces serving the Nawirrûs Covenant.