Monday is the first day visitors can make a free, online reservation to visit the 9/11 Memorial at the World Trade Center Site in Lower Manhattan.

Advance visitor passes to the 9/11 Memorial are required, officials said. Visitors must reserve advance passes for a specific date and time. Visitor passes are free and are available by clicking here.

For Americans, and for others who also believe in democracy, the protection of all under a Bill of Rights, diversity, and failrness under the rule of law, the 9/11 Memorial is hallowed ground.

The 9/11 Memorial will be dedicated on the 10th anniversary of the September 11, 2001 terrorist attack and will open to the public on Sept. 12.

The free, timed-entry passes will be required to clear security at the World Trade Center site. Online passes can be reserved up to six months in advance, and a limited number will also be available at kiosks at the Preview Site on Vesey Street, next to the World Trade Center site.

The 8-acre 9/11 Memorial contains two reflecting pools -- one for the North Tower, one for the South Tower -- and the names of the nearly 3,000 victims killed in the attack will be inscribed in bronze panels around the pools.

9/11 Memorial officials say the site's capacity is 1,500 and that they expect 4 million visitors in the first year.

On September 11, 2001, 19 al-Qaeda terrorists hijacked four commercial passenager jet airliners and intentially crashed two airliners into the Twin Towers in New York, N.Y., and a third airliner into the Pentagon, the U.S. Department of Defense headquarters in metro Washington, D.C.. A fourth airliner crashed in a field near Shanksville, Pa. after passengers attempt to re-gain control of the plane.