Guidebooks to brothels and prostitutes flourished in mid-nineteenth century Britain and America, particularly in the great cities of London and New York. This paper treats such guides as a form of imaginative mapping, associated with a ‘sporting’ male culture of sexually predatory men and an ideal city of male sexual opportunity. Such guidebooks offered to their readers a particular form of urban knowledge, primarily through the construction of the persona of the ‘man about town’, holding out the promise of ordering the confusing realities of the sprawling nineteenth-century metropolis. However, the guidebook genre necessarily admits something of the anxieties, ignorance and vulnerability of the would-be men about town who made up its readers, and this paper concludes that this literature should be considered as an elaborate ideological fantasy, constraining as well as constructing masculine identities, rather than simply evidence for the confident male appropriation of public space.