Topic: Tell me a short, interesting fact about

The Roman Empire was the first to widely use concrete for large-scale engineering projects, including the construction of aqueducts, roads, and the Colosseum. The concrete mix they used, called pozzolana cement, was made from volcanic ash from the town of Pozzuoli near Naples, giving it its name. It was stronger and more durable than today's mortar and helped create some of the most impressive architectural wonders of the ancient world.