This paper aims to discover why and how accessibility is fundamental to sustainable local development in heritage settings. We discussed the dimensions and variables of accessibility that control the development. Correspondingly, we proposed an interpretative framework for sustainable development planning and management of low urbanized spatial settings and accessibility for the Iglesiente Geo-mining heritage in Sardinia (Italy). The Iglesiente area is affected by a deep post-mining crisis that is reflected in poor socioeconomic conditions and an evident space oriented set of problems (a disorder in landscape matrix, low readability of space, scarce infrastructure and low accessibility). To revert negative trends of space-related problems, the paper proposes a theoretical model acting as an anticipatory landscape planning tool. The model copes with the context-specific problems in combination with theoretical findings. It acts at various scales through the definition of boundaries and variables of the internal and external environment, providing the territorial matrix of equity and cohesion. Furthermore, we argued the limitation and advantages of the model to its implementation capacity for the Geo-mining heritage and low-urbanized spatial settings. The empirical findings from an ongoing project about accessibility to territorial knowledge and services in the Iglesiente area, currently in progress, allow us to test and adjust the methodological framework in the next steps.