Where Grade and the singers of Hard Water reside (not limited to orcas)
The Jade Isle is a complex fortress of ice with little air, residents are forced to memorize each and every pathway the second they're born, lest they doom themselves to drown or be crushed.

Encased in a never-ending wall of fog, and surrounded by a mix of pack ice, smaller bergs, and thick ice, the entire 'fortress' is impregnable and the entire region is a death trap.