While the wealthy elites of ancient Rome lounged in sprawling, single-family townhouses ( domus ) or luxurious countryside villas, the vast majority of Rome's urban population lived a radically different reality. To house an unprecedented metropolis of over one million people, Roman architects engineered the insula (plural: insulae —literally meaning "islands"). These multi-story, high-density apartment blocks were the true engines of Roman urban life. They were overcrowded, structurally volatil