Abstract: Location ontologies axiomatize the relationship between physical bodies and the space that they occupy, and there is a rich literature on the philosophical underpinnings of these ontologies. Existing location ontologies have given primacy to the structure of what might be called abstract space. Consequently, the spatial properties and relations between physical bodies are extracted from the spatial properties and relations of the spatial regions that they occupy. In this paper, we take a different approach by beginning with the philosophical position of mereological pluralism, in which there are different mereologies for different kinds of entities. In particular, we make the fundamental ontological commitment that the mereology for spatial regions is different than the mereology for physical bodies. Different intuitions about location and different classes of physical bodies can be formally specified by imposing different conditions on this mapping, thus leading to different possible location ontologies. We propose an axiomatization of a location ontology and characterize the models of the axiomatization, up to isomorphism, by providing a representation theorem with respect to graph and poset homomorphisms.