visitors in 2012 with a turnover of about 1.9bn Euros. The same amount comes from the 70 million visitors that visit Lake Constance each year. This region is known for sightseeing, water-sports, winter-sports like Skiing, summer-sports like Swimming (sport), Sailing and recreation. It is also one of the few places where modern Zeppelin airships operate and 12–14 people can take a trip above the lake around various points of interests. In cooperation with tourism service providers, tourism organizations and public institutions in Germany, Austria, Switzerland and Liechtenstein, the International Bodensee Tourismus GmbH (IBT GmbH) is responsible for the tourism marketing of the Lake Constance region. Sights and cultural heritage The lake and the region around it have a substantial touristic infrastructure as well as many attractions and points of interests. Important are especially cities like Konstanz, Überlingen, Meersburg, Friedrichshafen, Lindau and Bregenz as they are the big hubs for boating tourism. The main tourism attractions are places like Rhine Falls, one of the three biggest waterfalls in Europe, the Mainau Island and Reichenau Island (UNESCO world heritage), the pilgrimage church Birnau, castles and palaces like Salem Abbey, Meersburg Castle as well as another UNESCO world heritage site, the Pfahlbaumuseum Unteruhldingen (German for Stilt house museum) as well as Church of St. George, Oberzell, Reichenau. The Alps reach almost to the east of the lake, producing great scenic beauty. The Pfänderbahn goes from top of the mountain right down, next to the lake in Bregenz. Cultural events Lake Constance is the location for the annual Bregenzer Festspiele, a well-known arts festival that, among other venues, takes place on a floating stage in Bregenz. The operas, plays and concerts performed are usually popular works, e.g. The Magic Flute by Wolfgang Amadeus Mozart or Rigoletto by Giuseppe Verdi. Since 2001, the ART BODENSEE takes place in Dornbirn. It is an annual meeting point for the exchange between collectors, artists and art appreciators. Biking Biking around the lake is also possible on the long trail called "Bodensee-Radweg". It brings its visitors to the most interesting sites and goes around the whole lake. Nevertheless, various shortcuts via ferries allow shorter routes and the trail is suitable for all levels. Note: There is also a trail that goes by the name "Bodensee-Rundweg". This road was intended for pedestrians so biking is sometimes not suitable or allowed. Hiking and pilgrim trails The 260 kilometers long Lake Constance