Walls are one of the oldest form of fortifications encountered in history. Walls were built as enclosures to defend settlements or seats of power. Sometimes entire cities were enclosed within the perimeter of walls. Walls of Fort have historically been constructed using various kinds of materials such as mud, dressed stone, mud enclosed within layers of stones, bricks and lime plaster etc.
A rampart is the broad-topped part of a defensive wall around a fort. It served as a walk-way to facilitate movement of soldiers during an attack. It also provided space to stretch and take better aim from the wall, at an attacking army. Ramparts, over time, have been constructed using a variety of materials such as dug-up earth, stone, concrete, timber or a combination of all these.
A bastion is a structure projecting outward at a certain angle to the fortification wall so as to facilitate attacks in different directions. Bastions became an indispensable part of fort architecture since the invention of gunpowder and cannons. In Indian forts various styles of bastions are encountered. Two broad categories are circular and angular.
A moat is a wide and deep trench that surrounds a fort. It functions as one of the initial line of defenses protecting the fort. Moats have been a feature of fort architecture since ancient times and continued to be important over the centuries. Some moats took very elaborated shapes in the form of artificial lakes and dams. Legends and oral traditions surrounding forts speak of moats filled with crocodiles and other deadly water-creatures to stall the progress of the enemy.
Gates are of strategic importance to forts as they hold direct access to the fortified area. A fortified structure may have many gates located at cardinal points. Gates of forts were often also built to commemorate victory by the winning side. These were mostly constructed with wood and iron. Many Indian forts have lofty and majestic gates which are highly ornamental.
A watchtower of a fort was a high and safe place from which guards kept watch over the surrounding area. Sentries stationed at watchtowers could spot an approaching army from a distance and make warning calls. Watchtowers were also often mounted with guns and cannons to provide an additional line of defense. Coastal watchtowers were of crucial importance in keeping a watch on approaching ships.
A parapet is a low wall or railing along the edge of a rampart. The parapet mostly contains embrasures or perforations for guns to be mounted and fired. It also functions as a protective barrier for the rampart. Some parapets are constructed with an incline towards the enemy to allow the defenders to shoot downwards. Parapets, over time, have been constructed using mud, timber, concrete and even iron.
A merlon is the solid part of the parapet which provides cover during firing. The space between two merlons is known as a Crenel. Merlons have been a part of fort architecture since the ancient times. Initially merlons used to be of a limited width. However, by the medieval period as warfare came to be dominated with novel weapons, merlons also developed complex forms.
A turret is a tower that is projects vertically from the wall of a fort. Sometimes it is also a smaller tower that is located on the top of a bigger tower. Turrets can be mounted with guns and offer the possibility of attack from an elevated part of the wall. Turrets can be open or covered. A turret is different from a watchtower as unlike the latter it is not a free-standing structure and is a part of the wall or a building.