What is up to 60 metres tall and runs through the centre of Sydney? The City of Sydney council will not say.

It is poised to unveil a major public artwork for George Street in the coming weeks, designed to be the centrepiece of the city's oldest street when it is finally turned into a pedestrian boulevard, shorn of cars and home to a new tram route.

People are turning their backs on Apple. Credit:Ben Rushton

Some councillors are comparing the expected public reaction to its unveiling in the same breath as the reaction to the Eiffel Tower.

Exactly what plans lord mayor Clover Moore and her colleagues at the council have been looking at has been a closely held secret. But intriguing details are now leaking out.