St Denis is historically so important and it is stunning. There are some fairly ridiculous comments on here about the safety of the area. It’s really fine. Yes, there are some angry young men there, but no one hassled me at all. I got the feeling that they respected tourists. The only thing I’d say is that you need a bit of cash as it was difficult to pay for coffee with a credit card - 15 euros minimum! A magnificent experience of a Gothic masterpiece that celebrates a marvellous moment in Christianity’s history.