Finding one’s way in complex indoor settings can be a quite stressful and time-consuming task, especially for users unfamiliar with the environment. Therefore, external support tools are necessary, especially in large complexes such as airports, train stations, hospitals, university or office buildings. So far there have been several different approaches to provide wayfinding assistance indoors. However, none of them has emerged to be efficient enough in order to act as a uniform solution for the wayfinding problem. Moreover, referencing to landmarks is not widely employed by wayfinding assistance systems despite the fact that landmark-based navigation is the most common way for people to navigate themselves through unfamiliar environments. Therefore, the aim of this work was to propose a new wayfinding assistance method for indoor environments that makes use of the landmark concept and for which the most important aspect is that assistance is provided to users where they actually need to make a directional choice. An already existing outdoor system, the Junction Network System, was used as a reference for this approach. Techniques from computational geometry and computer navigation systems were combined with the physical indoor space in order to realize the generation of a comprehensive system. The first step was to develop a model for automatically defining the locations, i.e. the decision points, where wayfinding assistance is needed in indoor settings based on the geometry, topology and semantics of the space, and the second step was to supply these points with a special type of landmark having the form of a signpost that provides all the necessary information through an enumeration technique. The system’s performance was tested carrying out site observations. The results revealed the potential of the system to act as a solution for the indoor wayfinding problem. The evidence of this research suggests that the proposed system can be applied without any changes or with slight modifications to different indoor space configurations. Additionally, the indication of decision points within indoor space can improve the functionality of indoor wayfinding systems by enhancing the conceptualization of turning instructions, while the representation of a route by a sequence of numbers provides a better conceptualization of direction instructions and eliminates the requirement to explicitly state the semantics of the indoor space in order to reach a destination.