Like other fields, Urban Geography has experienced an ‘infrastructural turn’ over the past two decades or so. This is in part because of the large interest in, and sometimes controversy over, infrastructures among state authorities, supranational bodies, businesses, civil society organizations and other actors. Another driver behind the infrastructural turn has been the realization that infrastructures offer a useful and effective lens on the contemporary urban condition, nature–society relations, everyday life and experience in the city, and politics and governance in specific spaces and times. This chapter reviews the sprawling literature about infrastructures in Urban Geography through discussion of four tensions that cut across it: between visibility and invisibility, connection and disconnection, standardisation and differentiation and normalcy and disruption. It then illustrates these infrastructural tensions through a focus on cycling infrastructures in London and São Paulo.