Fort Saint-Irénée, Military fort in 5th arrondissement, Lyon, France.

Fort Saint-Irénée is a pentagonal fort of the first Lyon belt, built of light tan and ochre stone blocks on a 150 × 180 m plan. Its entrance is a large arch with a paler stone surround, flanked by pilasters and topped by a flat cornice, with three arched windows above and grilled windows to either side. A plaque on the right pier reads "FORT SAINT-IRÉNÉE" above "ANDRÉ ALLIX".

Fort Saint-Irénée was built from 1832 to 1842 as part of Lyon's first defensive belt. The pentagonal fort, measuring 150 by 180 metres, housed the commander of the western sector of the Lyon garrison and could shelter nearly 800 men. Its powder magazine held 22 tonnes of powder, raised to 42 tonnes in 1880, enough to supply some 60 cannons. A kitchen, laundry, canteen, stables and several storehouses served daily life there.

From 1920 to 1946 the fort housed the Institut franco-chinois de Lyon, a French-Chinese institute for Chinese students. Since 2016 the Nouveau Institut Franco-Chinois has occupied part of the site, with a permanent exhibition recalling the original institute and a room for temporary shows of contemporary Chinese art.

The fort stands in Lyon's 5th arrondissement at 45.75440, 4.81216, on the site now used by ENSATT, with a small part assigned to the regional ONISEP office. The entrance is the central arch of the long stone wall, marked by a plaque reading "FORT SAINT-IRÉNÉE" and "ANDRÉ ALLIX". Look at the lower right of the entrance for the engraved number 380 with a horizontal stroke about a metre above the ground.

The number 380 is carved into the stone at the lower right of the entrance, beside a horizontal line about a metre above the ground. A study by the ASSIL association argues it is not an altitude in feet but a negative figure measured from a point at 660 m, perhaps the Fort du Mont-Verdun at 625 m.