This paper charts the attempts to construct an international map of the world using a standard projection and common conventions and symbols. The first part of the paper discusses the original incarnation of this idea, the International (1:1 Million) Map of the World (IMW), initially proposed by the German geographer Albrecht Penck in the early 1890s. The IMW was designed to challenge the idea that cartography was an inherently national science undertaken by, and for, specific nation states. Despite endless negotiations, delays and compromises, two world wars and the withdrawal of American support, the IMW project continued through the early and middle decades of the twentieth century, initially at the British Ordnance Survey and subsequently at the United Nations, only to fizzle out in the 1970s. The second part of the paper examines the Global Mapping Project (GMP), the latest manifestation of the same idea. Global Map, the first version of which was released in 2000, is an attempt to construct a single world map for the digital age. Like the IMW before it, Global Map is designed to facilitate a common, trans-national understanding of global problems. However, the technical, institutional and application challenges facing the GMP are different from those that confronted the IMW. Whereas the primary purpose of the IMW was never consistently defined, Global Map has a clearer environmental and educational objective. But if Global Map is to become an effective tool for sustainable environmental management and development, its advocates will need to learn the lessons of the IMW's failure and secure renewed international commitment to the value of international mapping.