Submarine cables for telecommunications were an early catalyst of globalization and of transnational corporate production networks and they continue to facilitate global economic activity. This article describes increasing demand from Internet and mobile phones as well as new uses for cables, such as oil exploration and high-energy physics. We trace the history of submarine cables and their geography from their early days to the Internet era, and analyze a global data set of cables at four intervals since 1979. Although the traditional triad locations (Western Europe, North America, and East Asia) are among the best connected, new networks in new places-notably Asia-are poised to become key network nodes in the twenty-first century. Based on cable capacity, the future submarine cable network looks very different from the old, suggesting new economic geographies and new world cities for a new world economy.