In classical cartography, people label "points of interest" on maps based on knowledge and research. In the TagMaps, the map points of interest emerge from the assortment of tags of geotagged photos
B. Sigurbjörnsson, and R. van Zwol. WWW '08: Proceeding of the 17th international conference on World Wide Web, page 327--336. New York, NY, USA, ACM, (2008)