This article describes a particular use of ontologies for visualising maps in a browser window. Geographic data are represented as instances of concepts in an ontology of transportation networks which was designed in close relation to GDF. These data are transformed into SVG, whereas the transformation is specified symbolically as instances of a transformation ontology. This approach is extremely flexible and easily extendible to include all kinds of information in the generated maps. The basic implementation technique is to use classes and instances of ontologies in an intelligent way. This article is an abbreviated version of the research report [12]. Keywords— semantic web, geospatial notions, ontologies, visualisation, scalable vector graphics, semantic techniques