Radisson Blu Hotel

Attempting to buck tradition, this landmark building is a gigantic disc made out of softly shining blue glass, 20 storeys, 96 metres high, 136 metres long and 85 metres wide. The state-of-the art hotel has an impressive 1500 bottle wine tower in the lobby, two restaurants, modern rooms of different varieties and an 18th-floor infinity pool where you can swim to a window with an incredible vista of the city skyline and the Taunus Mountains.