Pay £25 to climb into Orbit? Even Kapoor thinks it's steep

It was conceived in a cloakroom at Davos, during an encounter between the Mayor of London and Britain's richest man. Three years after Boris Johnson asked Lakshmi Mittal, the steel magnate, to finance a tower at the Olympic Park, the men played happy families yesterday as the Orbit was delivered to a far from doting city.

There were smiles, too, on the faces of the tower's designers, Anish Kapoor and Cecil Balmond. Neither they nor anybody else at a tightly choreographed press reception in east London would accept that Boris's brainchild was anything less than beautiful.

"I think it's awkward, it has its elbows sticking out," Mr Kapoor said, adding: "It is unsettling and I think that is part of this thing of beauty."

Mr Johnson, his hair challenged by the wind 115 metres (377 ft) above the Olympic Stadium, was more effusive. "It would have boggled the minds of the Romans," he said of the £23m tower, which is twice the height of Nelson's Column. "It would have dwarfed the aspirations of Gustave Eiffel."

Mr Kapoor, too, cited Eiffel in his defence of a sculpture that has been described as "Meccano on crack", a "crane crash" and "a lot of steel and money pissed into the sky, to no great purpose except the vanity of those involved".

"The Eiffel Tower was hated by everybody for a good many years," Mr Kapoor said, "and now it's a mainstay of how we understand Paris." The artist revealed he had received a note of support from Lord Rogers, co-architect of that other once-controversial Paris landmark, the Pompidou Centre.

Mr Kapoor had expressed frustration about design compromises forced by budgets and health and safety rules. The height of the tower was reduced by about a third, and Mr Kapoor called the safety mesh over the tower's spiral walkway "irritatingly over the top". He added: "You have to, kicking and screaming, find a way to negotiate."

The only dissent yesterday concerned the price of entry to the twin observation decks. Visitors will have to pay £15 on top of the £10 entrance fee to the park when the Orbit opens during the Olympic Games in July. "It's a hell of a lot of money," Kapoor said. "We wanted something very democratic."

Officials would not say if tickets would be cheaper after the Games. They revealed yesterday that, while some of the park will reopen a year after the Games, the area containing the Orbit will not reopen until at least Easter 2014, after a £490m redevelopment.

Before his first ascent of the completed tower, a giddy Cecil Balmond paused to look up at the vast, inverted, steel cone that hangs above its base. "We never wanted just to create a viewing platform," he said. "We wanted an experience. It's dark under the canopy – a black moment before you rise and the sky comes in. Mirrors distort the view so that you are not only looking out but being looked at as well."

Mr Kapoor said the Orbit would need a lick of red paint after about 30 years. Beyond that, he added, it "will last for as long as there is a cultural need for it."