After paying a modest admission fee, you are on your own to explore the Halifax Citadel. There is lots to see at this National Historic Site of Canada. Among the most noteworthy are the Army Museum, a barracks, garrison cells, the Cavalier Building, a school room, a 15 minute film about defending the harbor and plenty of old artillery. You can also dress up as a soldier and fire a rifle similar to those used in the 19th century.