The Siegfried Line, or Westwall, was a 630 km network of bunkers, tunnels, and “dragon’s teeth” fortifications built by Nazi Germany along its western frontier. Today, its ruined bunkers near Trier and Saarbrücken are infamous for ghostly encounters. Hikers and urban explorers report phantom marching, spectral soldiers patrolling the ruins, and disembodied voices echoing in the dark tunnels. Locals tell of glowing lights inside sealed bunkers and the chilling sound of machinery long since dismantled.