Visiting ground zero & lower Manhattan

The National September 11 Memorial and Museum is seen in the background as water flows in the south pool of the World Trade Center Memorial, Wednesday, Aug. 17, 2011 in New York. On the twin footprints of the towers are gentle waterfalls that empty into massive reflecting pools edged by bronze parapets with the names of the 2,983 people killed on 9/11 in New York, in a field near Shanksville, Pa., and at the Pentagon, along with victims of the 1993 bombing at the World Trade Center.

The Twin Tower Tridents are covered in plastic during the construction of the National September 11 Memorial and Museum Wednesday, Aug. 17, 2011, in New York.

The National September 11 Memorial and Museum is seen in the background as water flows in the south pool of the World Trade Center Memorial, Wednesday, Aug. 17, 2011 in New York. When the memorial opens, 225 swamp white oak trees will have been planted around the site. More than 400 are planned overall, creating an urban grove.

A construction worker cuts a metal rod inside the The National September 11 Memorial and Museum, Wednesday, Aug. 17, 2011 in New York. The memorial will be dedicated on Sept. 11, 2011, during a ceremony for victims' families. It opens to the public the following day.

Tourists look at a scale model of the proposed World Trade Center at the 9/11 Memorial Preview Site in New York on July 15, 2011.

Vistor's guides:
NYC 9/11 sites
Shanksville: Flight 93 Memorial
Pentagon Memorial

A collection of firefighters' uniform patches is displayed at St. Paul's Chapel in New York, July 19, 2011. A decade after the attack on the World Trade Center, Lower Manhattan draws roughly 9 million of the city's nearly 50 million visitors a year, including the area around ground zero.

Vistor's guides:
NYC 9/11 sites
Shanksville: Flight 93 Memorial
Pentagon Memorial

People relax under shade trees at the British Garden at Hanover Square in New York on July 15, 2011. Out of the ashes of 9/11 has risen a vibrant neighborhood packed with new restaurants and hotels, places to live and spots to shop, along with many ways to pay respects to an area some worried would never come back.

Vistor's guides:
NYC 9/11 sites
Shanksville: Flight 93 Memorial
Pentagon Memorial

A lunchtime crowd enjoys outdoor table service on Stone Street in New York on July 15, 2011. Out of the ashes of 9/11 has risen a vibrant neighborhood packed with new restaurants and hotels, places to live and spots to shop, along with many ways to pay respects to an area some worried would never come back.

Vistor's guides:
NYC 9/11 sites
Shanksville: Flight 93 Memorial
Pentagon Memorial

Tourists listen to a tour guide's memories of Sept. 11, 2001 in New York on July 28, 2011. A decade after the attack on the World Trade Center, Lower Manhattan draws roughly 9 million of the city's nearly 50 million visitors a year, including the area around ground zero.

Vistor's guides:
NYC 9/11 sites
Shanksville: Flight 93 Memorial
Pentagon Memorial

Tracy Gazzani, right, leads a walking tour past the Fire Department of New York Memorial Wall adjacent to the World Trade Center site in New York on July 28, 2011. Out of the ashes of 9/11 has risen a vibrant neighborhood packed with new restaurants and hotels, places to live and spots to shop, along with many ways to pay respects to an area some worried would never come back.

Vistor's guides:
NYC 9/11 sites
Shanksville: Flight 93 Memorial
Pentagon Memorial

Waterfalls empty into a massive reflecting pool at the National September 11 Memorial in New York on May 13, 2011. The memorial will open to the public on Sept. 12, 2011.

Vistor's guides:
NYC 9/11 sites
Shanksville: Flight 93 Memorial
Pentagon Memorial

In this aerial photo of July 28, 2011, a grove of trees surround massive square reflecting pools at the National September 11 Memorial in New York. The memorial will open to the public on Sept. 12, 2011.

Vistor's guides:
NYC 9/11 sites
Shanksville: Flight 93 Memorial
Pentagon Memorial

One World Trade Center towers over lower Manhattan in New York on Aug. 2, 2011. Once called the Freedom Tower, it will rise to 1,776 feet when completed.

Vistor's guides:
NYC 9/11 sites
Shanksville: Flight 93 Memorial
Pentagon Memorial