X-Nico

Fortresses of the German Confederation

Of these, six—Wesel, Cologne, Coblenz, Mainz, Germersheim, and Landau, were the real Rhine fortresses; the remaining three — Luxemburg and Saarlouis in the South, and Jülich in the North of the German Rhineland, shelter it in some measure against the French, Belgian, and Dutch frontier.

see also