Defensive fortifications are structures built to protect a place from attacks. These can include walls, towers, and moats, designed to keep enemies out and safeguard the people inside. Famous examples of defensive fortifications are the Great Wall of China and medieval castles, which were strategically constructed to withstand sieges and invasions. Throughout history, different cultures have developed unique fortifications based on their needs and available materials. For instance, the Roman Empire built extensive fortifications to secure their borders, while Japanese castles featured intricate designs to defend against samurai attacks. These structures not only served military purposes but also symbolized power and stability.