The Boiling Sea was a small landlocked body of water that bubbled and steamed during the summer months on Drall, thus warranting its name. The effect was not due merely to summer heat, but to a massive summer algae bloom. The algae released bubbles of gas when they died. The algae blooms provided food for the local ibbots. The banks of the Boiling Sea became a popular tourist attraction for the Drall and eventually sparked a lucrative offworld tourist industry, featuring resorts, health spas (such as the Luminous Gardens), hiking tours, and campgrounds. North of the sea was the region of Mastigophorous, ruled by the Duchess Marcha.