Beautiful inside and out! Marie Antoinette's cell was cool to see. I used my museum pass on this so it was a good value. Small attraction-can see it all in about an hour-two if you can read French :)
This is close to Sainte Chapelle and you can buy a ticket to both. This is where many figures of the French Revolution were held prisoner before execution, including Danton, Robespierre and Marie Antoinette.