This paper considers a problematic dynamic in the protection of natural World Heritage properties for sites that also possess significant cultural assets, but that fall short of the World Heritage designation 'outstanding universal value' standard for cultural significance. The destruction of cultural heritage places in natural settings is a global concern and we use an Australian case study to illustrate the argument that cultural assets located within natural properties should be given an allied protection status. We argue that protection problems arise, represented by a nature/culture binary trope, despite significant progress in using more holistic approaches, as exemplified by cultural landscapes. To demonstrate our argument, we consider controversy surrounding a development proposal within the Greater Blue Mountains World Heritage Area (GBMWHA), located in the state of New South Wales, Australia. We find that a development proposal to raise a storage dam wall triggers significant problems for protecting both natural and cultural heritage features across the GBMWHA landscape and, in this context, we recommend a reconsideration of the rigid natural/cultural heritage binary of World Heritage classifications.