Henri Rousseau was a self-taught artist who worked as a customs agent on the outskirts of Paris. His visionary paintings—in particular, those on the theme of the jungle—captivated the art world with their representations of lush plant and animal life painted with incredible detail and precision. Rousseau made “The Waterfall” in the last year of his life, and it may have been left unfinished: a few leaves on the branches of the tree in the left foreground lack some of the artist’s characteristic overlapping layers of color. Though Rousseau depicted exotic, distant locales, he never set foot outside France. His imaginary scenes were informed by visits to the Paris zoo and botanical gardens, and images from postcards, photographs, and illustrated journals.