Donauturm, Vienna

When viewed from afar, the Donauturm might appear to the untrained eye more like an odd oversized lighthouse in which one would not suspect in a 1,000 years contains a restaurant with a stunning panoramic view. Guests are delivered in a matter of seconds (30 actually) to either the viewing terrace at 150 metres from water level; or the restaurant, 15 metres further up. It is only after a short while that most guests realize that the entire room of the restaurant is, in fact, rotating. Signs are programmed to point out all the sights as and when they appear. A tip for visitors: any sunset observed from this point is not soon forgotten.