Differential locative marking is found in languages all over the world. Especially toponyms are well known to oft need less locative marking than other noun types, and it has been proposed that they express ‘where’ concepts. This study proposes a case study of differential locative marking in Makalero, a Papuan language of East Timor. It is displayed that the lack of perceptual limits and of an internal structure are notable parameters that differentiate the referents of so-called natural location nouns from nouns which indicate ‘what’ concepts. , where nouns fall into three categories: those which need no overt locative marking, i.e., can be zero-marked; those which are used with a semantically general locative verb; and those which can only be used with semantically specific locative verbs. Zero-marking of spatial relations occurs only in a specific construction where the nouns in question are used predicatively, suggesting that the syntactic equivalent of the ‘where’ category is a relational expression, not a noun. There is furthermore a certain degree of flexibility in Makalero locative constructions, and alternative expressions result in predictable semantic differences. These differences show that the lack of perceptual boundaries and of an internal structure are important parameters that distinguish the referents of so-called natural location nouns from nouns which denote ‘what’ concepts. More comparative case studies are needed to enrich our understanding of these notions and the properties characterizing them.