If you bike along the scenic, border-crossing Vennbahn, or Fen Railway, you’ll pass through a section that’s in Belgium, but where Germany is visible to your left and right—an unusual legacy of the days when Europe’s borders were more contentious and fluid. Constructed by the Prussian State Railway around 1889, the Vennbahn traversed land which, on German unification about 40 years earlier, had become German territory. After WWI, though, the many border changes mandated by the Treaty of Versailles handed the trackbed, the stations, and the infrastructure to Belgium. This provisional change,…
