Animal including salt water, hydrothermal vents, fresh water, hot springs, swamps, forests, pastures, deserts, air, and the interiors of animals, plants, fungi and rocks. Animals are however not particularly heat tolerant; very few of them can survive at constant temperatures above . Only very few species of animals (mostly nematodes) inhabit the most extreme cold deserts of continental Antarctica. The blue whale ("Balaenoptera musculus") is the largest animal that has ever lived, weighing up to 190 metric tonnes and measuring up to long. The largest extant terrestrial animal is the African bush elephant ("Loxodonta africana"), weighing up to 12.25 tonnes and
Return to the Centre of the Earth idea soon after, partly due to Richard Branson's world record attempts to circumnavigate the Earth by hot air balloon and thinking people will relate his music to the event. Soon after, Wakeman came across a newspaper article by Steven Spielberg, "who was talking about have sequels for making films, how you have a story and you spin up from the story for a whole new story, but you have a relationship, which is very comfortable for the people who listen a whole new story, new characters, but there's still a relationship." This prompted the thought in Wakeman's mind, after revisiting