Greece: Five hundred years before the birth of Christ, the small city-states of Greece began a period of cultural excellence, and none was more advanced than Athens. Discover the architectural, intellectual and artistic achievements of the period, and the elements that led to the end of the glorious "moment of excellence." China: Study the "dynasties of power" from the 2nd century B.C. through the rise of the first emperor to discover the achievements of ancient China. While uniting a vast land the Chinese built the 2,600-mile Great Wall, invented paper, printing, the compass and the world's first system of justice. Rome: Rome developed from a town on the Tiber River to a formidable power that dominated the world as it was known. See what researchers have discovered about life in ancient Rome, from the harsh life of a legionnaire on guard at Hadrian's Wall to the gladiators in the Colosseum.