They are the prized bounty of Haiti’s hard-fought struggle for freedom, taken in battle from European powers and then placed on top of the country’s most revered monument, Citadelle Henry, to guard against French occupation. National treasures, the 18th century cannons are priceless and come in various weights and dimensions. The largest of them, cast in iron, flank the mountaintop fortress outside of the northern city of Cap-Haïtien in the rural town of Milot. Smaller ones, cast in bronze with intricate markings hinting at their origins, have been safely tucked away behind locked doors in a m…