The Fort de Montmorency was built following the Franco-Prussian War to defend Paris. Located to the north of Paris in Montmorency, the fort was part of an outer ring of fortifications built in response to improvements in the range and effectiveness of artillery since the construction of the Thiers fortifications of the 1840s. It was built between 1875 and 1879 in accordance with improved principles of fortification developed for the Séré de Rivières system. The fort remains occupied by the military and is not open to the public.