Photo : Piazza della Repubblica
But why is Rome called the Eternal City?
Here’s one explanation :
Rome was known as the Eternal City even among the ancient Romans themselves. It was so called because the Roman people thought that no matter what happened to the world, no matter how many other empires might rise and fall, Rome would go on forever.
Rome was also called “an empire without end.” The phrase was popularized by The Eternal City (1901), a novel by Hall Caine that deals with a Utopian state in Rome. “Rome was not built in a day” in one form or other is a very old saying.
Travel tips : http://www.lonelyplanet.com/italy/rome