Coastal defense land battery at Outão, Portugal
A land battery is a special type of gun emplacement or anti-shipping naval interdiction fortification used in coastal defense to protect areas such as anchorages, harbors, and rivers. They are also used in restricted waters such as straits or channels, or coastal inland waterways which have the tactical and strategic purpose of area denial to the enemy.
In the modern era, land batteries were primarily built during times of war, such as those constructed in both World War I and World War II against the U-boat threat, or off North Vietnam during the Vietnam War. Those most recently constructed are based in Iran and Iraq.
See also