IntroductionThis paper compares the typology and the derived urban geographies of two infrastructural networks: the Internet backbone and the aviation network across European cities. While the latter consists of international intercity aviation links, the former consists of long-haul Internet Protocol (IP) links, which connect long-distance destinations and are responsible for the global character of the Internet (Malecki, 2004). This analysis aims to explore how these networks have developed across European cities, to understand their different topologies, and to compare the way the Internet backbone and the aviation networks interconnect the nodes of the European urban network. This topological exercise can feed a discussion of European urban geography by providing insights into the different roles European cities perform in these networks. As Derudder et al ( 2007) highlight, cities can derive functional centrality due to their roles in infrastructural networks.From an economic geography viewpoint, both the Internet (Malecki, 2002a) and the aviation network (Graham, 1998) facilitate the knowledge-based economy (OECD, 1996): while the Internet transports informational goods (O'Kelly and Grubesic, 2002), the aviation network transports the main actors of the knowledge economy, the people who form the managerial elites (Beaverstock, 2002;Castells, 1996), across the distributed centres of production and consumption so they can interact and acquire complex and tacit knowledge (Rimmer, 1998). In reality, the``spatial organization of the new international division of labour'' (Friedmann, 1986, page 69) is materialised by the advances in these two networks. The spatial distribution of these facilitators might be reflected in or affect the agglomeration of specific ö global ö economic activities (Matsumoto, 2007).From an urban geography perspective, both networks support the world city process (Castells, 1996). Telecommunications, just like transportation, are friction-reducing technologies, because of their ability to reduce the cost of distance (Cohen et al, 2002;Cohen-Blankshtain and Nijkamp, 2004), and enable global interactions by facilitating global economic activity (Malecki and Wei, 2009) and supporting the emergence of a world cities network. As Derudder (2006, page 2029) highlights,``in a networked