Ancien fort de Pattacreuse, fortification in Val-Cenis, France

The Ancien Fort de Pattacreuse is a ruined polygonal battery built between 1887 and 1889 at 2,395 metres on the summit of Mount Pattacroce. It had a ditch on three sides, an arched entrance portal flanked by an elongated caponier, and six gun sections separated by traverses. Twelve 12 GRC/Ret guns stood in barbette, eight facing north-west and four north-east.

Built between 1887 and 1889 on the summit of Mount Pattacroce at 2395 m, the battery was meant to stop an advance from the Colle del Piccolo Moncenisio, after the Moncenisio forts. French forts Mont Froid and Petit Turrà, higher up, made it vulnerable, so in 1904-1905 its guns went to Batteria Paradiso. The site stayed garrisoned, housed a cave battery (B5) of the Vallo Alpino, and in 1944-1945 German and RSI crews installed five 149 mm guns. The area passed to France with the 1947 Treaty of Paris.

The fort's name survives in two forms: Batteria Pattacroce in Italian and Ancien fort de Pattacreuse in French, a trace of the 1947 transfer of the Moncenisio area to France. Visitors can still make out the elliptical caponier beside the former main gate and the grey stone voussoirs that framed it.

Access to the fort requires a hiking route of around 14.5 kilometers round trip starting from the Saint Barthelemy chapel parking area. The hike demands moderate fitness due to the altitude and steep terrain, though it is manageable for those accustomed to mountain walking.

Under the 19th-century battery, the Italian army dug the B5 cavern battery as part of the Western Alpine Wall, armed with three 75/27 Mod. 1906 guns. In 1944-1945 five 149 mm guns were placed on the old battery's platforms, manned by Germans and RSI troops fighting around Mont Froid in March-April 1945.