The video titled "Ancient Greece 101 | National Geographic" provides a comprehensive overview of the legendary civilization of Ancient Greece, known for its significant contributions to art, philosophy, democracy, and heroism. The civilization, which expanded its influence from Spain to India, was a collection of over 1,500 territories known as city-states, each with its own rulers. Athens developed the first large-scale democracy, giving the Greek people representation and political power. The Greeks had a strong military that helped expand their empire and protect Greece from invaders. The video also discusses the cultural contributions of ancient Greece, particularly in the areas of art, architecture, religion, philosophy, and language. The civilization of Ancient Greece is considered legendary due to its contributions that have lasted for millennia.