As the outcome of joint work under the COST Action IC1203 ENERGIC the following paper has been published at the 9th International Symposium on Spatial Data Quality (ISSDQ 2015; La Grande Motte, France; 29 – 30 September, 2015): F. Ostermann, H. Huang, G. Andrienko, N. Andrienko, C. Capineri, K. Farkas, R. Purves: “Extracting and Comparing Places Using Geo-social Media”. In this paper, we presented the results of a first step towards a more in-depth study of semantic similarity of places through spatio-temporal clustering using Twitter and Flickr data sources.