Tourpedia (http://tour-pedia.org) is an open initiative which contains a linked dataset of tourism places, i.e. accommodations, attractions, points of interest (POIs) and restaurants. Tourpedia extracts and integrates information about places from four different social social media: Facebook, Foursquare, Google Places and Booking.com. The resulting knowledge base currently consists of more than 6M RDF triples and describes almost 500.000 places, each of which is identified by a globally unique identifier, which can be dereferenced over the Web into a RDF description. This paper gives an overview of the Tourpedia knowledge base and illustrates how new relations are discovered among places through Named Entity Recognition (NER) tools.