The Fort de Vancia is a former military installation built between 1872 and 1878 in the municipalities of Sathonay-Village and Rillieux-la-Pape, north of Lyon. It is part of the second belt Lyon and more generally the system Sere de Rivieres.
This belt of forts included
the forts of Bron, Vancia itself, Feyzin and Mont Verdun.
Wikipedia https://en.wikipedia.org/wiki/Fort_de_Vancia
Address 69580, France
Coordinates 45°50'19.083" N 4°54'25.74" E