Carleton Martello Tower is one of the oldest buildings in the city and has been designated as a National Historic Site of Canada since 1930.

Construction of the tower began in 1813, during the War of 1812, on a rocky cliff to guard the land approaches to the city.

In 1866 it received two 32-pounder guns that the New Brunswick Regiment of Garrison Artillery manned to defend the city in the event of Fenian raids.

[5] In late 1939, at the beginning of World War II, the 8th Anti-Aircraft Battery placed some machine guns on the upper level of the tower.

[clarification needed] On 1 May 1943 a Mark II Position Finder was added to the fire control equipment on the tower.