At over 2700 years old, Rome has seen a lot; it was the capital of the most powerful empire in the ancient world, fell to marauding barbarians, was rebuilt by Popes and most recently re-established as the capital of Italian culture. 

As such, Rome is a city made-up of recycled history. Many of the more modern buildings are built from the remnants of ancient structures whereas other elements have been imported from abroad to enhance the prestige of the city (Egyptian obelisks).