I think most people miss Saint Denis because it's out in the burbs on its own, but it's worth the trip. The monarch who created my last name was buried here along with pretty much every other French king with one or two exceptions, so my visit had special meaning for me.
The church is beautiful and full of stone coffins covered with graffiti from the French Revolution.
The neighborhood is very sketchy. Just be street smart and you'll be fine.
note: I actually visited in November 2011 but this site won't let me go back that far in the date, so that's not accurate. Ignore that.
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