Viollet Le Duc restored this donjon in the mid-1800s - the original dated back, probably, to the reign of Enguerrand VII at the end of the 1300s. Viollet made it popular (and accessible) although his method might, today, be frowned upon - in any case, we owe to him this delightful set of plans and section. The massive base of the tower gives way to a filigree of gothic arches towards the top, It is a weird hybrid of Scottish castle and French cathedral which, tectonically, makes perfect sense.
The tower was destroyed by the German army during the first World War, in 1917. It took 28 tons of cheddite to blow it up for no better reason than they could just do it and that it would shock people. People were suitably shocked and declared the ruins a monument against barbarism. 99 years afterwards, the story is forgotten, and we still act surprised when we hear that cultural heritage has been destroyed as act of warfare. In fact there's nothing new about it. The Chateau de Coucy has become another cute picture on Pinterest, filed under 'poche plan', 'thick walls', or 'quirky old buildings' - right where one day we'll find all the contemporary acts of destruction that might, one day, be forgotten.
I am not sure if this is a sour story, or if it is sweet - as architecture, form, and beauty did prevail after all.