What is fortress definition?

A fortress is a heavily fortified military stronghold designed to protect against enemy attacks. It is usually built with high walls, towers, and other defensive structures to provide security and defense to those inside. Fortresses have been constructed throughout history, dating back to ancient times when civilizations built fortifications to protect themselves from enemy forces. They have been used in wars and conflicts, usually serving as a base of operations for military and strategic operations. Some of the most famous fortresses include the Great Wall of China, Hadrian's Wall in England, and the Alhambra in Spain. In modern times, fortresses have evolved into highly advanced military installations, capable of withstanding missile attacks, cyber warfare, and other threats.