Château de Fontainebleau
Château de Fontainebleau is just 55 kilometres from the center of Paris. This massive palace has over 1500 rooms sprawled out on 130 acres of gardens and parks. It's one of the largest royal French châteaux to have ever been built.
Fontainebleau was much loved by Napoléon Bonaparte, who oversaw a lot of the restoration work. Napoléon III was another regular visitor, but as an example of the changes it has seen, during WWII the château was a headquarter for occupying Germans. It's now a UNESCO World Heritage Site.