Emerging and continuing advances in ambient systems and localization techniques have brought novel opportunities to develop context-aware navigation services in indoor environments. Diverse kinds of services delivered to the users can be provided by enabling real-time integration of contextual dimensions. In particular, continuous location-dependent queries can be considered as key elements for the development of different categories of context-aware services. However, most work on location-dependent query processing has been mainly oriented towards outdoor environments. This paper introduces a generic architecture for continuous location-dependent and navigation-related queries in indoor environments. A multi-level model of space is designed by taking into account contextual information and the hierarchical layout of an indoor environment. The semantics of a query language for continuous location-dependent queries are introduced, along with some motivating sample queries.