Roman bridges are ancient structures built by the Romans to facilitate transportation and trade across rivers and valleys. They were designed using durable materials like stone and concrete, allowing them to withstand the test of time. Many Roman bridges featured arches, which provided strength and stability, enabling them to support heavy loads. Some of the most famous examples of Roman bridges include the Pont du Gard in France and the Alcántara Bridge in Spain. These bridges not only served practical purposes but also showcased the engineering skills and architectural innovations of the Roman Empire.