Located on one of Paris’ two natural islands in the Seine river, the Palais de Justice is among the oldest surviving buildings of the former royal palace. The middle of three impressive buildings on the Île de la Cité (the other two are the medieval Gothic chapel Sainte Chapelle and the former prison the Conciergerie, which is now a museum), the Palais de Justice is notorious for its role during the French revolution, where more than 1,000 people (including Marie-Antoinette) were condemned to death before being imprisoned at the Conciergerie next door and executed on the guillotine.
Because the Palais is still used for judicial purposes today, visitors are not allowed to tour the premises. However, touring the Conciergerie and Sainte Chapelle is a great way to check out the Palais de Justice from the outside. Sainte Chapelle has an impressive collection of stained glass windows, and provides the closest look of the Palais de Justice available to the general public.