In 1957, UNESCO’s “Committee on Architecture and Works of Art” organized a competition for the decoration of the Organization’s permanent headquarters in Paris, inaugurated in 1958. Only eleven artists were selected, among which the Spanish painter and sculptor Joan Miró for the execution of a ceramic mural, a project for which he received the Guggenheim Prize the same year. The work is composed of two murals, the “Wall of the Moon” and “Wall of the Sun” placed perpendicular to each other. Initially placed outdoors, the works were later covered for conservation purposes.