Urban public parks can serve an important function by contributing to urban citizens' quality of life. At the same time, they can be the location of processes of displacement and exclusion. Despite this ambiguous role, little is known about actual park use patterns. To learn more about park use in three parks in Zurich, Switzerland, extensive data on visitor activities was collected using a new method based on direct recording via a portable GIS solution. Then, the data was analyzed using qualitative and quantitative methods. This paper examines whether geographic visualization of these data can help domain experts like landscape designers and park managers to assess park use. To maximize accessibility, the visualizations are made available through a web-interface of a common, off-the-shelf GIS. The technical limitations imposed by this choice are critically assessed, before the available visualization techniques are evaluated in respect to the needs and tasks of practitioners with limited knowledge on spatial analysis and GIS. Key criteria are each technique's level of abstraction and graphical complexity. The utility and suitability of the visualization techniques is characterized for the distinct phases of exploration, analysis and synthesis. The findings suggest that for a target user group of practitioners, a combination of dot maps showing the raw data and surface maps showing derived density values for several attributes serves the purpose of knowledge generation best.