Although the tragic events of Tuesday, September 11, 2001 are etched in the minds of many of us who lived through that dark day in American history, it's important to know that they are physically preserved forever at the site where the World Trade Center towers fell that morning.

Occupying half of the 16 acres at the World Trade Center complex, the National September 11 Memorial and Museum in New York is truly a place to learn, reflect and remember. Today, visitors are able to view sections of the slurry wall and other remaining structures at the foundation of the site where what was once the world's tallest buildings stood.

"We remember the towers standing, the towers falling, the devastation on the pile, the empty pit," said Joe Daniels, president, National 9/11 Memorial, to one newspaper interviewer. "And to move to a place of grace and beauty is something that the entire country can feel proud of."

Last weekend, Americans thorughout the country paused to remember that crisp morning when 19 al Qaeda terrorists hijacked four commercial U.S. jetliners, deliberately crashing two of the planes into the World Trade Center, and one into the Pentagon.

Aware of the three previous attacks that morning, passengers and crew members on a fourth plane heroically attempted to wrestle control of their hijacked plane from terrorists before it plunged into an empty field near Shanksville, Somerset County, in western Pennsylvania.

Nearly 3,000 people were killed on that day, the single largest loss of life from a foreign attack on American soil. The memorial at ground zero remembers those victims.

On last Sunday's 10th anniversary of the attacks, a dedication ceremony was held at the Memorial site for family members. On Monday, the Memorial was officially opened, while the museum is expected to open on or around September 11 of next year.

The 9/11 Memorial, which is partially open to the public, consists of two 30-foot deep reflecting pools, each pumping 26 thousand gallons of water per minute with cascading waterfalls set within the one-acre footprints of the original twin towers.

There are 2,983 names inscribed into bronze parapets surrounding the twin memorial pools – victims of both the 9/11 attack and also the Feb. 26, 1993 truck bombing at the World Trade Center. The engraved names are placed within nine primary groups – February 26, 1993, WTC North, WTC South, Flight 11, Flight 77, Flight 93, Flight 175, Pentagon and First Responders.

"I was sleeping when the towers were hit," said Connie Chen of Glastonburg Conn., who was a college student in New York when the 9/11 attacks were launched. "I woke up after receiving dozens of IM's (instant messages) from friends and family. I'll never forget the wall of debris, smell of burning rubber and the amount of confusion everyone had."

Another visitor to the memorial this week was Marc Barbiere, an emergency paramedic who was an early responder at the site that morning.

"I was responding when the North Tower collapsed," he said. "We rushed to set up our hospital on the pier, despite the lack of survivors."

Touch screen kiosks are located at the memorial to research the locations of each person on the memorial. Within these groups, names are arranged by affiliation, so that the employees of a company or the crew of a flight are together.

Visitors to the sacred site are offered some soft paper and a black crayon by staff people so they can trace the names from the memorial.

Also surrounding the plaza are 225 of the 400 planned, swamp white oak trees.

In 2003, the Lower Manhattan Development Corporation launched an international competition to design a memorial at the World Trade Center site to commemorate the lives that were lost in the attacks. That November, a 13-member design team, which included Maya Lin, designer of the Vietnam Veterans Memorial, and deputy mayor Patricia Harris, selected eight finalists.

"Reflecting Absence" was chosen as the winning design in January of 2004 and the final design for the site memorial was revealed in a press conference at Federal Hall in New York. Architect Michael Arad and landscape architect Peter Walker created the memorial design, following a global design competition that included more than 5,200 entries from 63 nations.

In August 2006, the World Trade Center Memorial Foundation and the Port Authority of New York and New Jersey began construction on the National September 11 Memorial and Museum. The following year, the World Trade Center Memorial Foundation was renamed the National September 11 Memorial and Museum at the World Trade Center.

When completed, the memorial and museum will cost over $700 million to build, and have an annual operating budget of over $50 million. Complementing the Memorial, a state-of-the art Memorial Museum, designed by Davis Brody Bond, LLP, will feature dynamic, interactive exhibitions, including artifacts and personal effects, a resource center, contemplative areas, and innovative educational programming.

Visitors will enter the Museum from an entry pavilion that features two of the original World Trade Center's signature architectural elements from the base of the Towers.

Admission is free, but requires a ticket for specific time. For more information about the three 9/11 national memorials, visit www.national911memorial.org