I lived around 8 years in St Denis and I can say a lot of things about it.

I think this site is very important and should be inscribed to the list. I know people are tight with this idea, because of too many christian sites already inscribed or whatever. But in fact this cathedral is largely more important than all the gothic cathedrals. I would be agree deleting Amiens, Bourges or Speir cathedrals to let the place to this cathedral.

I'm French and I know well our History and the standing of this place.

St Denis is not the most impressive cathedral in France, but it is the origin of the gothic architecture as you can read it for example in the "Pillars of the Earth" of Ken Follett. It's a really good novel to understand the importance of St Denis for France and UK in particular.

The royal city was a very rich place during the Middle Age. Now, it's the most important necropolis in Europe, nothing less.

The Saint who gave his name to the cathedral is one of the most famous Saint in our western culture, due to his particular biography. Decapitated, he took his head in his hands and walked several kilometers before finally falling at the current location of the cathedral. That's how his statue is very recognizable in the catholic churches: a man carrying his head in his hands. 

Culturally, St Denis stayed also in the french popular memories. A popular song named "Auprès de ma blonde" places St Denis with other rich and important places you know well : Notre Dame and Versailles. Chorus: "Je donnerais Versailles Paris et Saint-Denis Les tours de Notre Dame...".

In any case, if you are not conviced, be reassured, the inscription is not for tomorrow. There are politic points today not compatible with a such registration. The municipality is communist and doesn't pay attention to the Heritage. They prefer creation of social housings, already too numerous in the city, rather than supporting an application to the Unesco list. It could give attractiveness to st denis and it's not an option for the municipality, due to electoral reasons. Social mix is missing.

I conctacted the Municipality, and I can ensure you that today the project is totally abandoned.