Both Geographic Information Systems and Information Retrieval have been very active research elds in the last decades. Lately, a new research eld called Geographic Information Retrieval has appeared from the intersection of these two elds.The main goal of this eld is to de ne index structures and techniques to e ciently store and retrieve documents using both the text and the geographic references contained within the text. We present in this paper two contributions to this research eld. First, we propose a new index structure that combines an inverted index and a spatial index based on an ontology of geographic space. This structure improves the query capabilities of other proposals. Then, we describe the architecture of a system for geographic information retrieval that de nes a work ow for the extraction of the geographic references in documents. The architecture also uses the index structure that we propose to solve pure spatial and textual queries as well as hybrid queries that combine both a textual and a spatial component. Furthermore, query expansion can be performed on geographic references because the index structure is based in an ontology.