Conflict, Heritage and World-Making in the Chaco documents and interprets the physical remains and afterlives of the Chaco War (1932–35) – known as South America’s first ‘modern’ armed conflict – in what is now present-day Paraguay. It focuses not only on archaeological remains as conventionally understood, but takes an ontological approach to heterogeneous assemblages of objects, texts, practices and landscapes shaped by industrial war and people’s past and present engagements with them. These assemblages could be understood to constitute a ‘dark heritage’, the debris of a failed modernity. Yet it is clear that they are not simply dead memorials to this bloody war, but have been, and continue to be active in making, unmaking and remaking worlds – both for the participants and spectators of the war itself, as well as those who continue to occupy and live amongst the vast accretions of war matériel which persist in the present.