Hidden in the sense that it is not in Paris at all, the Chateau taking up the central part of the genteel town of Fontainebleu is a 40 minute train ride from Gare de Lyon, but it was a fabulously sunny day and definitely time to get into the green after winter's grey.
Smaller and older than Versailles, this palace of the French monarchs is undergoing some building restoration work at present so the Pope's rooms, so called, were closed, but the rest was open; room after room of gorgeousness, a veritable feast and a study in royal interior design over the centuries, including throne rooms, a ball room, library, reception rooms, Marie Antionette's bed chamber (another one), and many of Napoleon's personal effects, dinner services, campaign tent, jewels.
The gardens are extensive for strolling, picnicking, boating, and the like. A great day out when you want to escape the traffic fumes and Tom Cruise filming helicopter chases for Mission Impossible 6 in the skies of Paris.
