This study analyses the means through which indigenous stakeholders and British imperialists competed for influence in the shaping of Aden’s built environment, thus complementing a robust body of literature highlighting the importance of the port city within the framework of the world capitalist system. Yet in much of the historiography highlighting the colonial port city as an object of historical analysis, the coast of South Arabia – and the city of Aden in particular – remains overshadowed by the wealthy port cities of the Eastern Mediterranean. Crucially, the imperial politics of demarcation and development found in Aden grounds for experimental placemaking, a process consisting of military and civilian infrastructure projects and the securitisation of territory both within and beyond Aden’s walls. Attempts to territorialise space through the imposition of hard borders and infrastructure exemplify the colonial embrace of geo-spatial abstractions, a process that occurred alongside the consolidation of direct rule within Aden and the concurrent projection of capitalist market forces into the hinterland. British incapacity created room for local agents of change to contest the construction of colonial space; attempts to integrate Aden and neighbouring polities into the imperial orbit entailed negotiation, compromise and occasionally the use of violence.