The Mary-Ex Tower, 30 or St. Mary Ex 30.) is a 40-story skyscraper in London, the design of which is a mesh shell with a central support base. Capture the panorama of the city opening from it and the view unusual for central London. Residents behind a greenish shade of glass and a characteristic shape call it "cucumber", "cornichon" It is located in the center of London. It is the London headquarters of Swiss Re. The first to claim the title of ecological skyscraper. The lower floors of the building are open to all visitors. There are many restaurants on the upper floors.The building was built in 2001-2004The skyscraper does not have corners, which can not drain the wind currents down.The diameter of the building at the base is 49 meters, then the building gradually expands, reaching a flattering 57 meters at the level of 17 floors. Further, the design narrows, reaching a minimum diameter of 25 meters.The building is almost completely glass, its top is covered with a transparent dome. The building in height of 180 meters turned out to be economical: it consumes twice less electricity than other buildings of this type.