||The application of GIS tools for visitor monitoring facilitates a profound analysis of visitor flow patterns. Giving a visual impression of the distribution of visitors within an area via maps, interpretation of visitor use data is much easier and better. Furthermore, a GIS also allows to determine and analyse quantitative parameters of visitor use such as trail and visitor density. These parameters can also be used to characterise and compare different areas within a park. With a standardised approach, also comparisons between parks can be realised. Therefore, GIS is increasingly used in the area of visitor monitoring to assist recreation planners and park managers in their everyday work. This paper demonstrates how a GIS-based trail network analysis was used in the framework of a visitor monitoring project in the Danube Flood Plains National Park, Austria.