Our holiday this year was in the Champagne region of France, close to the River Marne. We took the opportunity to visit the National Memorial to the First World War (there are four in France altogether) which is at the town of Dormans. It was well worth the visit, with an especially interesting exhibition on the author, Maurice Genevoix, who fought in the war and wrote several books about his experiences, collectively known as Ceux de 1914. There is also an exhibition of trench art - items made out of shells, cartridges, supply boxes, etc. - which was very interesting as well.
The valley of the River Marne was much narrower than I had imagined, the slopes covered in vineyards, but also much woodland, and numerous small villages. The flat land on top of the ridges has extensive arable. The river is quite wide, meandering through the countryside, although some parts have been straightened for large canal traffic, and is certainly a significant military obstacle, but with numerous bridges. Seeing the vineyards made me realize how difficult it would be to move troops through them - you can go downslope fairly easily between the rows, but trying to move across them transversely would be very difficult!
We also took time to visit a war cemetery close to the town of Sézanne which included British and French soldiers who had fallen in the fighting. the French dated mostly from 1916-1918, the British from 1918, during the 2nd Battle of the Marne. It was very moving and caused much reflection, given the conflict going on in Ukraine, and a reminder that the background to my hobby has a reality that should never be forgotten.