Depends of the arrondissement. From 75001 to 75020 with the two last numbers are the number of the arrondissement. For example for the thirteenth arrondissement, the postal code is 75013. Sixteenth arrondissement has two postal codes : 75016 and 75116.
Did you mean Battle of Verdun? If you did, then it took place in Verdun! Verdun is a little north of Paris, France. Back when WWI started, Verdun was a big city, nowadays though, it is just a small town… Full Answer