When a friend offered Kevin Lynch, 48, tickets to Friday's grand opening of the One World Trade Center's observatory, he wasn’t going to pass up the chance. He pulled his son, eight-year-old Alexander, out of school and brought him along. They had come "to see history.” 

Lynch, from Long Island, New York, remembered as a child taking the elevator up the Twin Towers that occupied the space then. Seeing the new building was “almost like closure,” Lynch said as Alexander stood by his side, clutching an old tourist guide with the fallen buildings on the cover.

One World Trade Center’s observatory opened Friday, May 29, and for the first time, people were able to shoot up sky-pod elevators to the top of the country’s tallest building and take in the sweeping views. Tourists and New Yorkers alike came out in droves on opening day to ascend to the observatory. For some, the grand opening marked the chance to experience a building that symbolized the rebuilding of New York City after the Sept. 11, 2001, terrorist attacks. For others, it was simply a tourist destination with sweeping views.

Since city officials announced they would rebuild the site destroyed after terrorists hijacked two planes and directed them into the Twin Towers on the morning of Sept. 11, 2001,  critics have decried the commercialism of building One World Trade Center and the accompanying memorial and museum. In the terrorist attacks, both towers collapsed and more than 2,700 people were killed. Many bodies were never recovered from the site and some victim's families criticized the idea of building on a mass burial ground. 

Most people in the area on Friday, however, had good things to say about the new construction, a business complex completed in 2014 that houses, among others, major publishing company Condé Nast. When the first group went up to the observation deck at around 9 a.m., the area was packed with ticket holders, all waiting to fly up to the 100th floor. 

David Jimenez was among those who said the new 1,776-foot-tall building was the correct response. The building, conceived in 2005, went through numerous design iterations and inspired intense debate before officials settled on the final design, which features angular sides, a large spire at the top and, of course, the observatory.

It costs $32 for an adult, $26 for a child, and $30 for a senior to take in the view that shrinks the city to a consumable size. The observatory also displays time-lapse projections of New York City and a video of workers talking about what it meant to build the skyscraper where the Twin Towers once stood. 

WTC crowds The crowd waiting to go up to One World Trade Center's observatory on its opening day consumed most of the sidewalk outside of the skyscraper. Photo: Tim Marcin / IBTimes

Rich Delmotte, a 42-year-old firefighter from Nashville, Tennessee, said he “came here 10 years ago and it was just a hole in the ground.”

“We’ll just keep rebuilding,” he said.

Delmotte mingled outside the commotion with his wife, Kelly, a 44-year-old nurse, and daughters, Alexandra, 15, and Isabella, 6. They were headed to the memorial across the street but briefly stopped in front of One World Trade Center. Delmotte remembered being in firefighting rookie school in Nashville when the 9/11 attacks happened.

“[We] just sat there and watched the television and couldn’t believe what was happening,” he said. Delmotte said the family came out to pay homage and to take a few minutes to think about the attacks. His daughter Alexandra was so young at the time, “It doesn’t mean nothing to her,” he said. As for Isabella, the “choo choo” that brought the family into the city was the most important part of the day.

With his headphones dangling and work bag slung over his shoulder, David Jimenez briefly stopped his walk along Vessey Street on Friday to admire One World Trade Center. Jimenez, a 37-year-old New Yorker in the area on business, stopped to snap a photograph of the behemoth  -- an uncommon gesture for city dwellers, who usually bustle along, eyes to the ground. But he said he had never before noticed the way the angled sides of the building jut into a blue sky, like "a highway going up.” 

Jimenez said he planned to take his family to the top of the new building soon and, to get the full experience, would avoid seeing pictures taken from the observation deck.   

2015-05-20T225546Z_105192270_GF10000102042_RTRMADP_3_USA-NEW-YORK-WTC A view of the Manhattan skyline from the One World Observatory observation deck on the 100th floor of the One World Trade center tower in New York. Photo: Reuters

Joseph Passanisi, a 35-year-old emergency medical technician, said he felt honored to be part of the grand opening Friday, especially since many fellow EMTs died while searching for survivors in the aftermath of the 9/11 attacks. “Millions of people probably wanted to be here,” Passanisi said.

The long lines were a nuisance to those simply going about their day. Olga Kuznetsova, 51, works in One World Trade Center on the 33rd floor for publisher Condé Nast and said she thought the tourists were a bit of a hassle. She laughed as she remembered that, after the company moved away from Times Square, she had hoped the hassle of avoiding throngs of tourists would fade. “I thought we’d have less [tourists],” she said. “But now we have more.”

Those tourists came from as far away as Australia to wait for their chance to go all the way to the 100th floor. Stephanie Whitehead, 25, and Craig Mitchell, 29, queued up Friday morning waiting for 10:45 -- their designated viewing time. It was the final day of the Australian couple’s honeymoon and the newlyweds decided to cap the experience with this visit before taking the long flight home.

“[One World Trade Center] captures that American spirit of doing it bigger and better than everyone else,” Mitchell said with a laugh. As an added bonus, none of their friends could say they had been there yet -- so he said he would be able to brag.

The observation deck will likely continue to draw crowds for years to come, with officials predicting 3 million to 4 million visitors a year. That’ll be extra work for Jeremias Bourdier, a security guard who often stands outside the main entrance to One World Trade Center directing tourists to the two left turns that will take them to the memorial.

“I dream about it,” Bourdier, 25, of the Bronx, said. “Two left, two left.”

On Friday, he had a new task: directing tourists straight ahead to the observatory waiting line.