The next major step in millimetre astronomy, and one of the highest-priority items in radio astronomy today, is a large millimetre array with a collecting area 2 of up to 10 000 m . A project of this scale will almost certainly require inter national collaboration, at least within Europe, and possibly with other major partners elsewhere. In order to establish a focal point for this project within Europe, a study has been undertaken by the Institut de Radio Astronomie Mil Ii met rique (IRAM), the European Southern Observatory (ESO), The Onsala Space Observatory (OSO), and The Netherlands...