picture of the old cannon on the alter zoll am rhein in bonn, overlooking the rhine river.

alter zoll rhein bonn older customs old cannon germany german rhine river landmark historical deutsch deutschland history park travel military memorial defence bonner stadtbefestigung fortifications protection building garden europe heritage historic monument artillery gun aged fortress city stadtgarten three kings dreikapara nigen sault overlooking dreikoningen former bastion built 1644 river