Fort Mont-Valérien built
1841 CE.
Shown on the map at 48.873°, 2.213°.
Fort Mont-Valérien (French: Forteresse du Mont-Valérien, [fɔʁtəʁɛs dy mɔ̃valeʁjɛ̃]) is a fortress in Suresnes, a western Paris suburb, built in 1841 as part of the city's ring of modern fortifications. It overlooks the Bois de Boulogne across the Seine.
Text from the Wikipedia article Fort Mont-Valérien, licensed CC BY-SA 4.0.