Along with the Sainte Chapelle chapel, the Conciergerie is one of the few remaining parts of the ancient Palais de la Cité, which was the most extravagant royal palace in Europe during the Middle Ages, that are open to visit. After the royals abandoned the palace to move to the Louvre during the 15th century, the Palais de la Cité was repurposed into more useful tasks, including a prison. It was here that the princess Marie Antoinette was held for many long months before she was executed at the guillotine during the French Revolution. Her reconstructed prison cell along with the palace kitchens and other halls are open to visit.