Roman fortifications were military structures built by the ancient Romans to protect their territories and troops. These fortifications often included walls made of stone or earth, watchtowers, and gates. They were strategically placed along borders and in conquered territories to defend against invasions and to control local populations. The design of Roman fortifications varied depending on the location and purpose. Some forts, known as castra, were temporary camps for soldiers, while others were permanent structures. The use of legions allowed for rapid construction and effective defense, showcasing Roman engineering skills and military organization.