Natural heritage includes natural features or natural areas of outstanding universal value. At a national level, this value refers to the importance of ecosystems which can be considered as the spatial units representing the natural heritage of the particular area in terms of their values to people. Nature-based outdoor recreation represents an important service that interests millions of people and contributes to connecting them to nature, but it may also cause negative impacts in the form of pollution, erosion and habitats loss. We apply the ESTIMAP recreation model which provides a framework for a spatially-explicit assessment of local outdoor recreation and use it to identify and assess the natural heritage as a source of recreation services at a national level in Bulgaria. At the first stage of the study, we identify the natural heritage and the data sources to represent it in a spatially-explicit way. Then, we apply the module for recreation potential to assess the potential of the natural heritage to provide a recreation ecosystem service. At the third stage, the accessibility of the natural heritage is assessed in order to specify how the potential identified at the previous step can be really used. Finally, the recreation potential and accessibility are integrated into the recreation opportunity spectrum in order to develop the maps representing the ecosystem service supply provided by the natural heritage. The results are presented in form of a recreation potential map that reveals the capacity of natural heritage to provide the recreation potential, map of the accessibility of the natural heritage and map of the recreation opportunity spectrum representing the combination between the first two maps. The maps will be used for the development of an innovative geospatial platform designed to facilitate the access of the Bulgarian natural heritage to the European common knowledge and innovation markets. The results on the accessibility and recreation opportunity spectrum contribute to the development of the model in areas which were not covered by previous applications at the EU scale.