Over centuries, the Romans transformed a swamp on the banks of the Tiber into a settlement, then a city of brick and ultimately the gleaming marble core of the ancient world's greatest empire. Journey through massive Roman tunnels and trace the city's architectural and engineering evolution, including tombs, temples, monuments and aqueducts. See how the Romans converted an uninhabitable region into the home of some of the most impressive monumental architecture the world has ever seen.

• Kieran Bew