This paper presents a system which integrates a geographic information system of a building with computer vision. It uses only one camera, for example, the one of a mobile phone. Visual landmarks, such as frontal and lateral doors, stairs, signs, and fire extinguishers, are employed for localizing the user in the building and for tracing and validating a route for the user’s navigation. The developed system clearly improves the autonomy of persons with a very low vision during indoor navigation.