Whaam! by Roy Lichtenstein, in the Tate Modern, London. One of the major players in Pop Art, Lichtenstein’s work was often based on comic or advertising art. He used simple, common, and popular imagery to create social commentary. This is one of a number of pieces, based on actual comic book images, that Lichtenstein created about war. The Tate Modern is one of the world’s great art museums. If you’re in London, go.