From the 52nd floor of Silverstein Properties' 7 World Trade Center early on a summer's day, Lower Manhattan looks spectacular.
To the south and west, the Hudson River glistens in the sunlight while, to the north, Midtown's grid-patterned avenues and the green lungs of Central Park fade into the haze.
As an outsider, it is difficult to imagine the carnage that was wrought on this site on 11 September 2001, although the Ground Zero site - immediately in front of the building and busy with construction activity - provides a stark reminder.
As the sixth anniversary of the atrocity approaches, Lower Manhattan's commercial real estate market is coming back stronger than ever.
Downtown - usually thought of as the area south of Canal Street - is becoming a magnet for the types of occupier that would not traditionally have considered it an option.
Although the area is regarded as Manhattan's financial district, a wave of legal and creative occupiers is moving in, while residential developers have been boosted by generous incentives implemented following 9/11.
"Downtown is changing," says Gus Field, executive vice-president of Cushman & Wakefield in New York. "A lot more people are living Downtown, schools are opening and top retailers are moving in. We will continue to see the profile of office end-users expand to every other kind of business you would find in Manhattan."
Advertising companies have been linked with several buildings Downtown, including Sapir Organization's 600,000 sq ft 100 Church Street.
And, while financial occupier Moody's took 670,000 sq ft at the Skidmore Owings Merrill-designed 7WTC - the first building to be completed at Ground Zero - more than 80,000 sq ft was let to law firm Darby & Darby. Indeed, law firms accounted for three of Downtown's top-10 largest transactions during Q1.
Previously, tempting professional and media companies such as these away from their Midtown comfort zone would have been difficult.
The effect of the migration has been obvious, with Downtown vacancy rates dropping to 7.2% for Q1, down 4.4% on the previous year.
According to Cushman & Wakefield, oversupply is no longer considered a problem, especially for grade-A buildings, where the vacancy rate stands at just 6.6%, down from more than 12% at the start of 2006.
Financial occupiers are, of course, contributing significantly to these figures. John Zuccotti, chairman of landlord-developer Brookfield Properties, argues that growth is driven by the financial sector.
"All financial occupiers want bigger trading floors of 80,000-100,000 sq ft in buildings of 1.5m-2m sq ft," says Zuccotti. "That's what is driving the commercial market. It spins off on to law firms, printing firms and everyone else."
A trend towards bigger floorplates has been branded "trading floor envy". Goldman Sachs, for example, is building a 43-storey tower with trading floors of 75,000 sq ft at Battery Park City. That is prompting jealous looks from competitors such as Merrill Lynch, which is eyeing the World Trade Center, as well as Vornado Realty's Hotel Pennsylvania site in Midtown, for its own sizeable requirement.
Peter Riguardi, president of the New York office of Jones Lang LaSalle, which is advising the occupier, says a time frame on the decision has not been agreed.
Alongside the availability of glitzy new buildings such as 7WTC, occupiers are scuttling away from their preferred Midtown addresses because of rapidly escalating rents.
The average rent in Midtown has hit an all-time high of more than $70 (£34.97) per sq ft - up 28% during the course of 2006, says C&W - while $100 (£49.96) per sq ft "trophy rents" are becoming the norm for prime buildings. Although rents are low compared with those in London's West End, Manhattan occupiers are keen to find alternatives.
As Neil Goldmacher, executivevice-president and principal at Newmark Knight Frank, observes: "When the Midtown market is as tight as it has been - and when it's more expensive - occupiers tend to look to Midtown South and Downtown."
Field adds: "The strength of the Midtown market has caused a flattening of the market geographically. Prior to the most recent increases, some occupiers would consider only Midtown, whereas now the market has flattened and we are seeing occupiers move out."
As part of that flattening, and driven by restrictions on availability, rents Downtown, as in Midtown, are shooting up. For grade-A buildings, average rents have bounced from $38.50 (£19.24) to around $47.50 (£23.73) per sq ft over of the past year. In the World Financial Center and at 7WTC, prime rents are hitting around $70 (£34.97) per sq ft.
Nonetheless, occupier demand remains healthy and, in the medium term, new subway links beneath the World Trade Center are expected to play a major part in bringing even more firms Downtown. JLL's Riguardi says Downtown will become a "24/7 community", and believes the vast underground station will allow Midtown and Downtown to "move together".
"Most subway lines will have direct connectivity to that station, which will become a huge destination," he says.
The past six years have been tough for the Downtown market, but there seems to be a genuine optimism that new buildings, rising rents, an influx of occupiers and improved infrastructure are beginning to have an effect. New York's developers and real estate brokers will be pleased that the sun is beginning to shine.
London v New York - the debate rages
A debate is raging on both sides of the Atlantic over whether New York or London is the world's 21st century financial capital.
While New York's financial clout has been relatively unchallenged during the past 100 years, some suggest this was a 20th century phenomenon that is rapidly looking out of date.
This spring, in an article headed "Is New York no longer the world's financial capital?", New York magazine suggested that the Big Apple looks "parochial" compared with "exotic" London. It noted that Goldman Sachs employs 6,500 in the UK capital - including global chief administrative officer Edward Forst.
London, it said, is a centre of "financial innovation", while the New York Stock Exchange is suffering a "drought" of initial public offerings by international companies.
New York's City Hall seems acutely aware of the issue. Its desire not to remain complacent about its place in the world is a key driver behind Mayor Bloomberg's PlaNYC (see p80).
British-born Richard Sexton, global business development partner at Newmark Knight Frank in Manhattan, is one of those who believes London has something unique to offer as a global financial centre.
"London has a strategic advantage because of the time zone, which means you can talk to Asia in the morning and the Americas in the afternoon," he says.
While acknowledging that this advantage is not new, Sexton says a willingness to work longer and an increased worldwide business emphasis on an "immediate response" means London's attractiveness has grown.
Growth and rejuvenation
Peter Riguardi, president of the New York office of Jones Lang LaSalle, is not convinced by that argument, however.
"London's location is an advantage, no question, but New Yorkers are willing to come in early and work late to get the job done. There is a supply of employees available 24/7," he says.
Riguardi believes New York has as much to offer as a vibrant financial centre as its European rival. Both New York and London, he says, are experiencing "growth and rejuvenation", and neither city has anything to fear from young pretenders such as Frankfurt.
"There are lots of different metrics you can use to compare New York and London. But it's pretty clear the two are kicking everyone's butts at the moment," he says.
That may be true. The argument could be settled over the next decade as the markets make their judgment.
City's investment market steams ahead
The New York investment market had a record-breaking 2006, with $34.7bn (£17.34bn) of deals completed during the year.
In the first quarter of 2007, that showed no signs of slowing, with $13.6bn (£6.8bn) of deals concluded.
Among them was Macklowe Properties' purchase of eight Midtown buildings for a total of $7.2bn (£3.6bn), equivalent to $1,100 (£549.9) per sq ft.
Since then, prices have continued to rise. Somerset Partners recently paid Taconic Investments $510m for 450 Park Avenue - a record-breaking $1,589 (£794) per sq ft.
Despite the generally buoyant investment picture, some are wary of the macroeconomic situation and what it might mean for the market in the longer term.
Barry Gosin, chief executive officer of Newmark Knight Frank, says: "Since 1993, we've seen a 14- or 15-year bull run - and the bull's got to get tired."
Gosin's colleague James Kuhn, president of the New York specialist broker, also appears concerned about the market's future economic prospects.
"The dollar is dropping precipitously and, although a cheaper dollar makes business boom now, if it drops too much and stops being the universal currency, we could see an interest rate spike," he says.