Gorky's House (Ryabushinsky Mansion)

The incredible Art Nouveau Ryabushinsky Mansion was once the home of a wealthy Russian merchant. It is in a part of Moscow which doesn't get a lot of tourists, but it's a true gem that merits a visit. During the revolution, the owner fled Russia and the house was given over to the famous writer Gorky. Aside from the beauty of the house, there's also an interesting exhibition with the author's personal belongings and documents. Very interesting on several levels.