Abandoned place – Sainte-Marie-aux-Mines, France

Deep within the dense, undulating canopy of Saint-Dié-des-Vosges, France, lies a hidden military relic of a bygone era. Completely swallowed by the relentless Vosges forest, this subterranean stronghold remains invisible from above, its concrete bones slowly dissolving into the damp earth beneath an impenetrable shield of green.