Salvador Dalí, 1931. Melting watches in a Catalan landscape. The defining single image of Surrealism. MoMA, New York.
From Wikipedia
The Persistence of Memory is a 1931 painting by artist Salvador Dalí and one of the most recognizable works of Surrealism. First exhibited at the Julien Levy Gallery in 1932 and sold for $250, The Persistence of Memory was donated to the Museum of Modern Art (MoMA) in New York City two years later in 1934 by an anonymous donor, where it has remained ever since. It is widely recognized and frequently referred to in popular culture, and sometimes referred to by more descriptive titles, such as "The Melting Clocks", "The Soft Watches" or "The Melting Watches".