A "fort" is a strong building or structure designed to protect people and resources. Historically, forts were built by armies to defend against enemies and to control important areas. They often have thick walls, towers, and sometimes a moat to keep attackers out. Many forts are located in strategic places, like near rivers or on hills, to provide a better view of the surroundings. Today, many forts are preserved as historical sites and can be visited by the public. They offer a glimpse into the past, showcasing military life and architecture. Some famous forts, like Fort Sumter and Fort Knox, are well-known for their historical significance and unique features.