The study explored the value that local residents place on historic ruins, focusing on their socio-economic value. It also explored the implications of conventional Cultural Heritage Management’s (CHM) indifference to this. Using in-depth data from 22 residents in Kilwa Kisiwani World Heritage Site in Tanzania, the study found that residents not only attach cultural value to the ruins, but also consider them a conservation project and tourist attraction, from which they can earn money and get employment and see infrastructure and social facilities developed. It also found that the destructive activities of illegally digging to construct toilets and water collectors, letting domestic animals wander in the ruins, quarrying old underground walls for coral stones, and lighting fires are partly the result of limited socioeconomic benefits, inconsistent business opportunities, complaints about employment and payment, and few feasible alternatives for making a living. By engaging with the socio-economic discourse, this study broadens our understanding of the integration of conservation in the broader social agenda, and contributes to the economist-anthropologic debate on CHM. It informs heritage managers and policy makers on alternative strategies that would maintain the sustainability of the heritage.