I'm currently reading Caesar's Women by Colleen McCullough and on a map at the back of the book, Roman insulae (singular: insula) were mentioned as being apartment buildings that were up to 12 storeys. Although of course the Romans built lots of impressive architecture and were amazing engineers, I was surprised by 12-storey apartment buildings. I've looked online and haven't been able to find any evidence of such tall apartment buildings. 4 or 5 storeys, yes. 12, not so much. Does anyone know? @Joel Harris, I know you're an ancient history buff. Do you know anything about Ancient Roman apartment buildings? I gather that however tall they were, it was a bit dangerous to live in the upper floors because of the fire risk and getting out in time...