sentences:  Bus services within the city are provided by Stadtwerke Konstanz GmbH.Additionally Konstanz and Friedrichshafen have been connected by the two (since 2008, three) catamarans "Constance" and "Fridolin" since 2005.It is home to one or more prehistoric pile-dwelling (or stilt house) settlements that are part of the Prehistoric Pile dwellings around the Alps UNESCO World Heritage Site.