The Louvre, in Paris, is the most visited gallery in the world. It has existed for more than 200 years and displays 35,000 works of art, including the Mona Lisa by Leonardo da Vinci. In 2012, the Louvre opened a sister gallery in the town of Lens in northern France, and the Louvre Abu Dhabi is scheduled to open in 2015.
The Metropolitan Museum of Art, in New York City, has the second highest number of visitors. It is unusual because it has one of the most impressive collections on the planet but no fixed admission fee; visitors pay whatever they can afford.
The third, fourth, and fifth most popular art museums—the British Museum, the Tate Modern, and the National Gallery—are all in London. Although the British Museum and National Gallery were founded in 1752 and 1824, respectively, the Tate Modern didn't open its doors until 2000. It is located inside a former power station.