This is Château de Vincennes, a 14th century castle. From the website:
A symbol of the modern French state. The building affirms the power of the monarchy: it guarded the capital, whilst at the same time protecting the kings against uprisings. It was at the heart of the French monarchy until 1682, when Louis XIV chose to settle in Versailles. The keep was used as a prison from the 16th up to the 19th century: Fouquet, the Marquis de Sade, and Mirabeau were held here. Under Napoleon I it was transformed into a barracks and arsenal, and the fortress protected Paris during invasions in the 19th century.
The onsite information is mostly about Charles V (the room is his main chamber). From Wikipedia:
The defeats of the French and the capture of the King by the English in the Hundred Years War, as well as uprisings of the Parisian merchants under Etienne Marcel (1357–58) and a rural upraising against the crown, the Jacquerie (1360), persuaded the new French King, Jean II of France and his son, the future Charles V, that they needed a more secure residence close to, but not in the center of Paris. The King ordered the construction of a fortress at Vincennes with high walls and towers surrounding a massive keep or central tower, 52 meters (172 feet) high. The work was started in about 1337, and by 1364 the three lower levels of the keep were finished. Charles V moved into the keep in 1367 or 1368, while construction was still underway. When it was completed in 1369–70, it was the tallest fortified structure in Europe.
From an onsite panel:
The painted decorations were done by prisoners. Those in this room were by Monseigneur Boulogne, confessor of Napoleon I, imprisoned on his orders.
These are good steps. If you must have a circular staircase, you should have shallow, broad steps like these.
A castle without a moat.
Other buildings on the site include the Sainte-Chapelle and the Queen’s Pavillion. Why the queen needs an entired large building I don’t know. There’s a King’s Paviliion off stage to the right
Tour Saint-Jacques tends to dominate the skyline. From Wikipedia:
This 52-metre (171 ft) Flamboyant Gothic tower is all that remains of the former 16th-century Church of Saint-Jacques-de-la-Boucherie (“Saint James of the butchers”), which was demolished in 1797, during the French Revolution, leaving only the tower. . . . The church, with the exception of the tower, was demolished in 1793; preservation of the tower was a condition of the contract by which the church was bought for the value of its building materials. In 1824 it was being used as a shot tower to make small shot. It was repurchased by the City of Paris in 1836 and declared a Monument Historique in 1862. A statue of the saint was installed on the top of the tower during the 19th century. During the Second Empire, the architect Théodore Ballu restored the tower, placing it on a pedestal and designing a small city park around it.
Church of Saint-Eustache
FInally, I went to the Museum of Illusions, which doesn’t photograph very well so have lots of me instead.