 Most people who visit Paris plan to see at least one of its great museums. Coming up, we'll get a peek at some of its lesser-known specialty museums, those one-of-a-kind gems that are hidden in plain sight. A lot of people sort of want their unique experience of a city that so many people go to. The Louvre, on the other hand, is more than just home to Mona Lisa. It's the world's largest and busiest art museum, and its architecture contains clues to the history of France.