HSBC Main Building

Foster won the commission in 1979 to replace a third headquarters that itself stood on the site of the bank's first Hong Kong office, and the result abandoned almost everything conventional about a tower. There is no central concrete core: eight clusters of four aluminium-clad steel masts run up the building's edges, carrying five storeys' worth of enormous suspension trusses from which the floor modules are hung in sections, the way a bridge deck hangs from its cables. Steel components were prefabricated by a shipyard on the Clyde and floated out to Hong Kong for assembly, and mirrored 'sunscoops' on the south face bounce daylight down through a ten-storey atrium onto the plaza below. That ground-level plaza, kept open on feng shui advice, still doubles as a public route between Statue Square and Des Voeux Road, guarded by the bank's two bronze lions, Stephen and Stitt, cast in 1935 and rubbed shiny by passers-by touching them for luck. At roughly £500 million it was, briefly, the most expensive building ever constructed.