Topic: Tell me a short, interesting fact about

The Romans were known for their advancements in engineering and construction, but did you know that the Roman Empire used concrete over 2000 years ago to build the Colosseum? Rumor has it that they even mixed crushed volcanic rock, pozzolana, into their concrete to make it stronger and more resistant to seawater. This pioneering technology is still used in modern construction today, demonstrating the Romans' remarkable foresight and ingenuity.