Avsnitt 4

Following in the footsteps of the greatest explorers of the Poles, Planet Earth, with the help of British Navy helicopters, leads the BBC's high-definition cameras to film from above the incredible spectacle of humpback whales as they feed. Other cameras film under the ice . These are never-before-seen images of our planet and the great protagonists of the ice worlds: polar bears, seals, walruses and the heroic emperor penguins, who manage to survive at deadly temperatures, defending their fertilized eggs. The civilizations of the past have left tombs, imperial palaces, temples. That is, places of power or worship . Instead, the most impressive remains of Roman civilization are almost always places where people had fun: theaters, amphitheatres, like the Colosseum, or the Baths, like the grandiose ones of Caracalla, in Rome, where people walked, met, with large spaces for hot and cold water pools, gyms, outdoor games.