In 1974 the New Babylon project officially came to an end with a large exhibition in the Gemeentemuseum Den Haag. Because he lacked room to store the vast collection of constructions, maquettes, maps and structures he sold them all to the museum. In 1999 "Constant's New Babylon: City for Another Life", opened at the Drawing Center in New York. It was his first solo exhibition in the United States and was curated by Mark Wigley. There was a symposium conducted in conjunction with the exhibition.