The mapping of cultural ecosystem services through online public participation GIS (PPGIS) has predominantly relied on geographic entities, such as points and polygons, to collect spatial data, regardless of their limitations. As the potential of online PPGIS to support planning and design keeps growing, so does the need for more knowledge about data quality and suitable geographic entities to collect data. Using the online PPGIS tool, “My Green Place,” 449 respondents mapped cultural ecosystem services in Ghent by using all three geographic entities: point, polygon, and the novel “marker.” The three geographic entities’ accuracy was analyzed through a quadrat analysis, regressions against the collective truth, the Akaike information criterion, and a preference test based on the survey’s outcomes. The results show that the point reflects the weakest the collective truth, especially for mapping dynamic cultural practices, and the marker reflects it the strongest. The polygon’s performance compares to that of the marker’s, albeit slightly weaker. The marker delivers a more nuanced image of the respondents’ input, is simpler to use, and has less risk of spatial errors. Therefore, we suggest using the marker instead of the point and the polygon when collecting spatial data in future cultural ecosystem services research.