Redoubt

[4] During the English Civil War, redoubts were frequently built to protect older fortifications from the more effective artillery of the period.

From 1715 onwards, the Order of Saint John built a number of redoubts in Malta, as part of an effort to improve the coastal fortifications of the islands.

[7] During the siege of Malta of 1798–1800, Maltese insurgents built a number of fortifications to bombard French positions and repel a possible counterattack.

[9] The American Revolution defenses at West Point, New York included several redoubts, forts, and the Great Chain with links weighing more than 100 pounds each that Continental Army military engineers stretched across the Hudson River.

The purpose behind the West Point defensive system was to prevent the British Army and Royal Navy from gaining control of the Hudson and splitting New England off from the mid-Atlantic and southern states.

Typically a region is chosen with a geography favouring defence, such as a mountainous area or a peninsula, in order to function as a final hold-out to preserve national independence for the duration of the conflict.