Resumen
We discuss an OpenStreetMap (OSM) mapping party organised during the Free and Open Source Software for Geospatial (FOSS4G) Europe 2015 conference held in Como, Italy in July 2015. While primarily the mapping party was organised as a conference social event, there was also the serious goal of collecting and adding geographic data to the OSM database of Como city. Our paper describes the organisation, planning and structure of the mapping party. Results show that considerable amounts of data was collected and uploaded to OSM. Overall there was very good interest in the mapping party with 40 participants. While the majority of participants were delegates at the conference and consequently could be considered highly skilled GIS practitioners only a very small number had actually contributed data to OSM in the past. We discuss the key lessons learned and overall positive and negative aspects of this mapping party.