Skull Island places Skull Island atop an entryway into Hollow Earth that is responsible for its population of giant monsters and plant/animal hybrids. The 2019 film Godzilla: King of the Monsters reveals the existence of a Hollow Earth with portals that Godzilla uses as shortcuts to move faster around the globe. The 2021 film Godzilla vs Kong features an expedition into Hollow Earth to harness a mysterious energy source and find Kong's ancestral home. Due to a strong reverse-gravitational effect, Apex Cybernetics has developed HEAVs which are specialized crafts able to withstand the pressure exerted by the gravity field. The 2019 film Iron Sky: The Coming Race is a Finnish-German comic science fiction action film directed by Timo Vuorensola. TV In the Tiny Toon Adventures episode "Journey to the Center of Acme Acres", a series of earthquakes shake up the city, causing Plucky and Hamton to fall into a crater in the ground. They fall for hours before finally reaching the center, which is hollow. In the 1987–1996 animated Teenage Mutant Ninja Turtles series episode "Turtles at the Earth's Core", the turtles discover a cavern on Earth where dinosaurs still roam. The Spider Riders series of books and anime take place in an "Inner World" inhabited by humans, cybernetic battle spiders, and intelligent insects. Cleopatra 2525 The anime series Gurren Lagann is initially set in an underground civilization due to the surface of the world being ruled by Lordgenome. The Transformers: Cybertron cartoon series features a character, Professor Lucy Suzuki, who believes in the Hollow Earth Theory. The Japanese anime Gaiking: Legend of Daiku-Maryu has the protagonists spend much of their time in a hollow Earth called Darius, home of an empire of humanoids that are currently amassing a force to invade and conquer the surface world. The French cartoon Les Mondes Engloutis (known in English as Spartakus and the Sun Beneath the Sea) involves protagonists descending through a maze of caves into a subterranean world of different space and time, inhabited by various peoples. Sanctuary has a Season 3 storyline that deals with Helen Magnus and her team finding and visiting Hollow Earth. In Detentionaire, the main antagonist of the series known as "His Eminence" is from a long lost race of ancient reptilian humanoids who retreated beneath the earth and lay dormant for thousands of years. In Doctor Who Series 5 (2010), episodes 8 and 9 The Hungry