Wow, the Seine is all wiggly!
Just like the lower part of the Rio Bravo*, err, as we call it the Rio Grande.
* Mexico calls it the Rio Bravo and if you go to google maps it is called Rio Bravo on the map.
With all the bends and loops of the lower Seine, I never thought it was an effective defensive position. It certainly wasn’t for the French in 1940 and won’t be for the Germans in a few weeks, but in both cases there were no effective organized troops to try to defend it.