They took Verdun on their way--so did the Germans in 1870.

Verdun in French hands closed this trough to the invaders.

It closed it because the low hill which bears the town was strongly
fortified and was surrounded by lower ground. Such artillery as was in
existence was not of a sufficiently long range to place upon the hills
about Verdun which we have described as the rim of the bowl. The town
of Verdun was situated on both sides of the river and commanded all
the bridges. It was, in fact, the stopple in the mouth of the
bottle-neck passage leading into North Central France, the passage
through which ran the main road and, later, the railway from the
frontier nearest Paris to the capital.

But when the modern developments of artillery came, then Verdun, the
old fortress that Vauban built for Louis XIV, lost its value. It was
commanded by the surrounding hills and the French moved out of the
town and the Vauban fortifications and built on the surrounding hills,
on the rim, to go back to our figure, the forts which were the defence
of the town when the present war began, forts arranged quite like
those of Liege or Antwerp and some four or five miles away from the
town. But bear in mind these forts were designed, like the old
fortress and fortifications of the eighteenth century, to bar the road
from the Meuse and from Germany to the Plain of Chalons and the level
country west of the Argonne. When the Germans came south through
Belgium and got into the Plain of Chalons from the north they had
turned the whole Verdun position and had got into the region it
barred by another route; they had come in by the back door; Verdun
was the front. Not only that, but they are there now and have been
there ever since the first days of September, 1914.

When one hears about Verdun as the gateway to Paris or anything else
one hears about the Verdun of the past. It was not the door to Paris
but the outer door to the region around Paris, to the Plains of
Champagne and Chalons. But as the Germans are already in these plains
the taking of Verdun now would not bring them nearer to Paris; they
are only fifty miles away at Noyon, on the Oise, and they would be 160
at Verdun if they took the city. If they took Verdun they would get
control of the Paris-Metz Railway, and if they then drove the French
away from the trough we have been describing they would get a short
line into France, and a line coming from German territory directly,
not p