Camouflage is a passive defense system that aims to conceal military assets, personnel, and equipment from enemy detection and observation.

Moats are primarily designed to create a physical obstacle that hinders enemy access to the fortification, making it more difficult for them to launch attacks.

A fortress is a large and heavily fortified structure designed to protect a specific location or area from enemy attacks and invasions.

A parapet is a fortified wall or rampart surrounding a castle or town, typically featuring a crenellated top to provide cover for defenders.

A fort is a fortified structure designed to protect a harbor or river entrance, typically armed with cannons and other weapons to deter enemy ships.

A bunker is a small, fortified structure designed to provide cover for soldiers during combat, typically made of concrete or earth and equipped with firing positions.

A bridgehead is a fortified position established on the far side of a river or obstacle, designed to protect a bridge or river crossing and prevent enemy forces from crossing.

A turret is a fortified tower or structure projecting from a castle or city wall, typically equipped with weapons and used for observation and defense.

A coastal battery is a fortified position equipped with artillery and other weapons, designed to protect a harbor or coastal area from naval attacks.

A moat is a fortified ditch or trench surrounding a castle or town, typically filled with water or other obstacles to deter enemy attacks.

A redoubt is a small, fortified position designed to protect a specific point or area from enemy fire, typically constructed in the form of a square or circular earthwork.

A strategic point is a fortified position designed to control a strategic location or passage, such as a mountain pass, river crossing, or harbor entrance.

A city wall is a fortified structure surrounding a city or town, designed to protect it from enemy attacks and invasions.

A fortress is a large and heavily fortified structure designed to protect a specific location or area from enemy attacks and invasions.

A redoubt is a small, fortified position designed to protect a specific point or area from enemy fire, typically constructed in the form of a square or circular earthwork.