2 Best Sights in Paris, France

This imposing high-walled château, on the northern edge of the Bois de Vincennes, was France's medieval version of Versailles. Built and expanded by various kings between the 12th and 14th centuries, it is now surrounded by a dry moat and dominated by a 170-foot keep, the last of nine original towers. The royal residence eventually became a prison holding, notably, convicts of both sexes—and "the doors did not always remain closed between them," as one tour guide coyly put it. Inmates included the philosopher Diderot and the Marquis de Sade, and the alleged spy Mata Hari was executed in its dry moat bed. Both the château and its cathedral, Ste-Chapelle—designed in the style of the Paris church of the same name—have undergone a spectacular restoration, returning them to their previous glory. If you speak French, the free 90-minute tour is worthwhile; otherwise, consider spending €3 for the English audioguide. The entrance to the lovely Parc Floral de Paris is just behind the chateau.

One of the few remaining structures in Paris from the Middle Ages, this little castle was most famously the home of Queen Margot, who took up residence here in 1605 after her marriage to Henry IV was annulled. Margot was known for her many lovers (she supposedly wore wigs made from locks of their hair) and reputedly ordered a servant beheaded in the courtyard after he ridiculed one of her companions. The street is said to be named after a fig tree she ordered cut down because it was inconveniencing her carriage. Perhaps for that reason there's a fig tree planted in the elegant rear garden, which is open to the public. Notice the cannonball lodged in the front facade commemorating a battle here during the three-day revolution in July 1830. Built for the archbishop of Sens in 1475, the castle was extensively renovated in the 20th century and is today home to the Bibliothèque Forney, a library that also stages temporary exhibitions drawn from its extensive collection of fine and graphic arts.