Fort Neuf de Vincennes
12th arrondissement of Paris, France
The Fort Neuf de Vincennes ("New Vincennes Fort") is a fortification built on the grounds of the Château de Vincennes, on the east side of Paris. While the old chateau had been a significant fortification in its time, by 1840 there was a need for a modern fort at that location, capable of using and defending itself against artillery fire. A new bastioned fort was built to the east of the historic chateau.
Fort data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).