Fortifications built during the 17th or 18th centuries were designed to withstand artillery bombardment by cannon, mortars and guns of all sizes. They have a distinctive star shape ground plan with sharp-pointed bastions and thick earth walls, some faced with stone. The outer defences consisted of a broad external ditch, beyond which was the glacis (the open killing ground). Associated with these fortifications are barracks and other buildings, as well as a parade ground.
Fort George, near Inverness, was built after the Jacobite uprising of 1745-6. It is still used as a military barracks as well as being a visitor attraction. These sites are noted on historical OS maps as well as on certain contemporary military maps held in the National Library of Scotland.