The city walls extend 4.6 kilometres (2.9 mi), with the southern portions of the ramparts forming a part of the Citadelle of Quebec.

However, by the late 19th century, several deteriorating facilities associated with Quebec City's fortifications were demolished, although the primary defences remained.

The city's defence complex, including its ramparts, were designated as the Fortifications of Québec National Historic Site in 1948.

[4] The initial settlement, the Habitation de Québec, included a trading post, residence and a redoubt with elevated walls.

[7] However, several flaws were evident in the 1745 design, with the rampart's flanks being exposed against several high points further west of the city and its hasty construction in the midst of a panic over a potential attack.

[8] The condition of the ramparts was partly what led General Louis-Joseph de Montcalm to assemble his forces outside the walled city on the Plains of Abraham to meet the British; which resulted in the capitulation of Quebec.

[8] The city's ramparts were used by the British forces in the following year, allowing them to hold out against a French siege in 1760 until reinforcements arrived by sea.

[6] The ramparts were used again fifteen years later, when soldiers of the British Army and the Canadian militia held off another siege in 1775 by American forces.

[9] The American Revolutionary War sparked a renewed interest in improving the city's defences, with a series of wood and earthworks formed along the redoubt and heights of Cap Diamond; acting as a temporary citadel.

[9] The plans included the extension of the 1745 ramparts along with several outworks added to its walls, a citadel on Cap Diamant, and several defensive works in the Plains of Abraham.

[12] When British forces withdrew from the city in 1871, a number of sites were demolished to make way for new developments, including the old military gates of the ramparts.

[4] Wood and green sandstone quarried from the borough of Sillery make up a significant portion of the materials used to build the fortifications.

[6] The underground battery was built to reinforce the portion of the ramparts thought to be the weakest by doubling the available firepower around that point.

[6] The ramparts of Quebec City form a part of the Fortifications of Québec National Historic Site of Canada, which is made up of several sites associated with the historic defences for the city’s Upper Town and Lower Town; along the north shore of the Saint Lawrence River to the Montmorency River in the borough of Beauport.

[4] At one point, the depth of the defensive works surrounding Upper Town was 75-metre-wide (246 ft) when factoring its the city walls, ditches, outworks, and the glacis.