Freedom Tower rises above Ground Zero to take its place on the New York skyline

Almost a decade after the world watched helplessly as two of New York's most iconic landmarks were reduced to rubble, a new future has risen from the ashes at Ground Zero.

One World Trade Center, aka the Freedom Tower, has finally joined the Manhattan skyline, standing defiantly over the site of the worst terrorist atrocity to befall American soil.

Its steel frame now stands at 58 stories tall and is starting to inch above many of the skyscrapers that ring the site - with a new floor being added every week.

 Imposing: Growing at a floor a week, Freedom Tower is fast becoming a feature on New York's skyline

Defiant: Its steel frame, already clad in glass on lower floors, now stands 58 stories tall and is starting to inch above many of the skyscrapers that ring the site

The black-granite fountains and reflecting pools that mark the footprints of the fallen twin towers are almost finished.

The memorial plaza won't be complete when it opens on Sept. 11, 2011, and a tour of the site last week makes clear that work around it will continue for years.

Mud is still plentiful at ground level, and for now the site is dominated by the same concrete-grey shades that blanketed lower Manhattan after the 9/11 attacks.

But the agency that owned the trade center and has spent nearly a decade rebuilding it is aiming to deliver a memorial experience on 9/11/11 that closes one chapter and ushers in a new experience, where ground zero again becomes part of the city's everyday fabric.

'We want people to be able to see that downtown does have this incredible future to it,' said Chris Ward, executive director of the Port Authority of New York and New Jersey. 'The work will not be done on that day. What we hope will be done is the sense of frustration.'

For now, the complexity and scale of the construction is evident in every corner.

Workers labor around the clock. During the busiest shifts, around 2,800 people — mostly men — labour amid tangles and ravines of steel. In one steel cavern that will become a transit hub concourse, showers of orange sparks fly as welders install trusses weighing up to 50 tons.

From the top of One World Trade, the view is spectacular, as it was from the twin towers, even though the building stands at 680 feet, less than halfway to its planned 1,776-foot height.

Visitors to the upper floors can see the grand sweep of the Hudson River and New York Harbor, dotted with container ships, all the way to Sandy Hook at the northern tip of the Jersey Shore. People at ground level can now see the tower, too, from a growing number of places in the city and across the river in New Jersey.

A huge portion of the reconstruction of the trade center is taking place below ground. The underground halls that house the memorial are cavernous, and in their unfinished state look like some unexplored temple in an Indiana Jones movie.

The huge boxes that hold the waterfall pits visible from the surface are somehow suspended from the ceiling, held up by pillars that don't seem big enough to support the blocks' massive weight.

A maze of tunnels, catwalks and narrow, temporary staircases connect the various underground levels.

To rebuild, work crews needed to excavate nearly 100 feet down below, but rather than reroute service and demolish the tunnel, they merely propped it up on huge pilings and dug beneath it. The tracks, still encased in their old concrete tube, now sit suspended in mid-air as work takes place below, above and on either side.

Ward said he hoped people will be able to see in six months that, despite the ongoing construction, the site's days as a disaster zone are ending.

'It will be a place where you meet a friend for lunch. Where you meet a date. Where you race across the plaza and beneath the trees to get out of the rain,' he said. 'We want New Yorkers to make their own narrative there.'

 Imposing: Growing at a floor a week, Freedom Tower is fast becoming a feature on New York's skyline

 Defiant: Its steel frame, already clad in glass on lower floors, now stands 58 stories tall and is starting to inch above many of the skyscrapers that ring the site

 Don't look down: The mammoth black-granite fountains and reflecting pools that mark the footprints of the fallen twin towers are largely finished

 On top of the world: Ironworkers align steel columns high in the sky

The Twin Towers moments after being hit by the planes on 9/11 and the immediate aftermath with diggers trying to clear the area after the columns came down