National Museum of Western Art
Cottet's paintings can be found in many museums worldwide, including the Pushkin Museum of Fine Arts in Moscow, the British Museum, the National Gallery of Art in Washington D.C., the Musée d’Orsay in Paris, the Hermitage, the University of Michigan Museum of Art, the Ohara Museum of Art, the Smithsonian American Art Museum, the National Museum of Western Art, the Zimmerli Art Museum, the Fine Arts Museum of San Francisco, the Metropolitan Museum of Art, and the Musée Rodin.