The 9/11 memorial plaza opened its gates at 10 a.m. under tight, airport-style security. Visitors walked among hundreds of white oak trees on the eight-acre site and gazed at the water on the exact spots where the World Trade Center's twin towers stood.
They also ran their fingers over the names of the 2,977 people killed in the terrorist attacks in New York, at the Pentagon and in Pennsylvania, as well as the six who died in the bombing of the trade center in 1993.
"It's so surreal. When we walked in, those images were popping in my head from 10 years ago," said Laura Pajar, a pharmaceutical-industry researcher from Las Vegas. "But when I saw the memorial, all of that went away. This is so peaceful, and you kind of forget about what happened and you look toward the future."
Jim Drzewiecki, a volunteer firefighter from Lancaster, N.Y., said he was shaking as he walked up to the memorial entrance and stood next to the pools.
"It makes it clear how devastating - to see the number of people who lost their lives at this location," he said. He added: "I'm actually still shaking. It could have been me on that flight. On any one of the flights. ... There's not much that separates us."
Eileen Cristina, of Lititz, Pa., who a decade ago volunteered her services as a massage therapist to the landfill workers who handled the trade center debris, was moved to tears.
"For me, the water element is very important, because water is so cleansing. Water can cleanse the energy of the area," she said.
Visitors sat on benches and clustered for photos in front of the trees. Some wept, some embraced. Others made pencil-and-paper rubbings of the victims' names. Sun gleamed off the bronze parapets on which the names were inscribed.
The memorial plaza opened to the families of the victims for the first time on Sunday.
Jelena Watkins, whose brother died at the trade center, came from London for Sunday's 10th anniversary of the attacks. At the memorial, she and her husband held up their two children so that they could see their uncle's name. Luka, 5, ran his hands through the water that pools under the names.
"I love it. It was a huge relief to see that it's actually beautiful," Watkins said. "It's the right feel. It's just so right. It's so spacious."
Although thousands of construction workers have come and gone from the site over the years, Monday marked the first time that ordinary Americans without a badge, a press pass or a hard hat were able to walk the grounds where the victims were once entombed in a mountain of smoking rubble.
About 7,000 people were issued tickets for opening day. Some 400,000 have reserved tickets for the coming months, memorial president Joe Daniels said.
"For the vast majority of the world, the images that they remember from this site are very difficult. It's the recovery period, it's seeing those images of the towers falling. So when they come on now and see this place that's been transformed into a place of beauty, it's exciting," Daniels said.
Admission is free, but access is tightly controlled. Visitors need to obtain passes in advance, allowing them to enter at a specified time. No more than about 1,500 at a time will be allowed in.
Visitors must empty their pockets, walk through a metal detector and send their handbags and backpacks through an X-ray machine.
The museum portion of the memorial complex is still under construction. The museum pavilion, a tilting structure that evokes the sections of the trade center facade that remained standing after the towers fell, is scheduled to open on the 11th anniversary of the attacks.
Eventually visitors to the underground portion will be able to gaze at such sights as the giant slurry wall, built to keep the Hudson River from flooding the trade center's foundations, and the survivor's staircase that allowed so many people to flee to safety.
The cost of the memorial and museum has been put at about $700 million, with an annual operating budget of $50 million to $60 million. The nonprofit organization that runs the project has raised about $400 million in private donations and is seeking federal funds so that the memorial and museum can be free of charge.
The centerpiece of the memorial is the two giant, square pits and reflecting pools that sit in the footprints of the two towers.
The waterfalls cascading down the four walls of each fountain are the largest such fountains in North America.
The letters in the names have been entirely cut out of the bronze, with only emptiness beneath them.
Skyscrapers are now pushing upward all around the plaza, and the roar of construction will be a constant at the site for some time.
One World Trade Center, the spire once called the Freedom Tower, is now 1,000 feet high and well on its way to becoming the tallest building in the U.S. at 1,776 feet - higher even than the twin towers. The steel skeleton of the new 4 World Trade Center is 47 stories high and counting.
The memorial foundation has arranged for a separate entrance for relatives of the victims and plans to set aside certain days or hours where the plaza will be open only to firefighters, police officers and other emergency workers.
Associated Press writer Verena Dobnik contributed to this report.