The 43-Meter Dome in Rome That Heals Its Own Cracks

Ancient Rome grew from Palatine Hill huts to rule 60 million people — and outlasted its greatest disaster. From the calculated founding on April 21, 753 BC and the Republic of 509 BC to the 70,000 dead at Cannae in 216 BC, it traces 11 aqueducts carrying a million cubic meters a day, self-healing pozzolana concrete, the 43.4-meter Pantheon dome, and a citizenship policy that turned a census of 900,000 into 4 million before the sack of 410 AD and the final fall in 1453.