Visit: Palace of Versailles, Place d'Armes, 78000, Versailles France
Unbelievable as it may seem, this complex was initially a humble brick-and-stone hunting lodge built for Louis XIII. His son Louis XIV (the Sun King) went his own way, turning it into an enormous monument to architecture, art, and the fine taste of the French monarchy. There are no half-measures in its conception or execution (it has more than 1,200 fireplaces!).
That opulence is most evident in the Galerie des Glaces (Hall of Mirrors), a 75m-long ballroom lined with statues and busts. It has 17 arched windows, each embellished with 21 individual mirrors. For those keeping score, that means light beams off 357 mirrors in total.
Versailles is one of the most visited attractions in France, as well as a UNESCO World Heritage site.
The audio guide that comes along with this ticket will give you all sorts of info and stories about the history of this magnificent complex.