This paper describes two ontologies of wayfinding with multiple transportation modes in an urban area. One ontology is developed from the perspective of the traveler, which is different from the perspective presented by the public transportation system. Our hypothesis is that the ontology of the traveler is a subset of the ontology of the system, thus leading to the idea of nested ontologies. The ontologies are derived from a case study of wayfinding in the city of Hamburg, Germany. The information on the system's ontology is derived from the material provided to the traveler, e.g., maps, timetables, station layout and signs.