Kati Peterson walked through the new 50-foot-long glass tunnel, under a brick archway and into the old light-filled courtyard of the Isabella Stewart Gardner Museum.
She did not say a word, but a soft smile gave her away as she took in the statues and tropical plants. On the day the Gardner opened its $114 million expansion to the public, Peterson, 27, was visiting the 109-year-old museum for the first time.
“It’s gorgeous,’’ she said. “I didn’t expect this at all.’’
That was one snapshot from opening day, when the Gardner - after more than a week of private parties, black-tie concerts, and formal dedications - showed off the space designed by architect Renzo Piano to anyone who wanted to see it. Admission was free, though visitors were supposed to get a timed ticket to keep the museum from getting too crowded.
A range of people cued up for the 11 a.m. opening, as museum caterers offered platters of miniature cider-doughnuts.
There was Peterson, who had heard about the Gardner’s expansion and wanted to see it in person, and folks like Christopher and Cynthia Gorton, South End residents who have been going to the museum for years and were eager to see how the new fit with the old. Christopher Gorton mentioned architect Piano.
“I want to see what he did, and I know they had to take down a carriage house,’’ Gorton said, referring to one of the project’s few controversial elements, when the historic building was demolished to make way for construction.
The $118 million project - $114 million for the new building, $4 million for renovations to the palace - includes new galleries, a music hall, café, education spaces, green house, artist residences, gift shop, and living room, a space meant to serve as a kind of lounge. The expansion also created a new entrance.
Before the public opening, the Gardner held a ribbon-cutting at 9 a.m., with Mayor Thomas M. Menino attending. He spoke of his appreciation for the museum and praised director Anne Hawley, who, he added, had invited him to visit the Gardner not long after he first took office. Menino said he had eagerly awaited the finish of the project.
“I said to my wife: ‘When am I going there? When is my turn?’ ’’ Menino said. “My turn is today.’’
It was also Rossanna Lizama-Soto’s turn. The Roslindale woman showed up a few minutes before 9 and ended up being the first person to arrive. Gardner staff members pulled her out of line and into the pre-opening ceremony. There, in front of Menino and other dignitaries, she was awarded a lifetime membership to the museum.
To think that just a month ago Lizama-Soto brought her daughter Tahina, 7, to the Gardner and was crushed to find the museum closed for the final stretch of its expansion project. Then, yesterday morning, Lizama-Soto was listening to the radio and heard about the Gardner’s grand opening. She decided to stop by.
“I think I’m still in shock,’’ she said, adding that she will probably be back on Sunday because Tahina was in school yesterday.
“I’m going to have to be very careful about telling her,’’ said Lizama-Soto. “She’s going to be very upset that she was not here.’’
Yesterday’s opening was not just for the public. Gardner staff said they were excited to see, for the first time, how people will use the new building.
“You can build a living room, but will people actually plop down and sit and have conversations?’’ said Peggy Burchenal, the museum’s curator of education.
The early indications were positive.
Erika Swanson, a Cambridge mother, sat on a couch next to her son, Ian, 3, who was drawing a muscle-bound super hero. One couch over, artist Lee Mingwei, who conceived the living room idea, spoke to a visitor.
While much attention has centered on the Gardner’s new space, many visitors were moved by the work done in one of the museum’s old spaces. The Tapestry Room, in recent decades stuffed with chairs and a stage to host the Gardner’s concert series, has undergone a dramatic restoration. The chairs are gone, the windows unblocked, and the tiles cleaned and reglazed.
“It’s really exciting to see it the way it was originally supposed to be arranged,’’ said Emily Tricco, visiting with her mother, Beverly. “It’s a whole new set of details to explore.’’
Michael Malvers, who owns a towing company in Haverhill, brought his mother, Huguette Juliano, to the museum he loves to visit.
“To see these tapestries, to realize how much it took to stitch them, it’s amazing,’’ he said.
Christopher and Cynthia Gorton, making their way into the Tapestry Room, said that any concerns they had about the Gardner’s new space were gone. Christopher Gorton particularly liked the glass walkway.
“Other than being beamed up by Scotty,’’ he said, “it’s not a bad way to come into the old place.’’
Geoff Edgers can be reached at firstname.lastname@example.org. The Isabella Stewart Gardner Museum, 280 The Fenway, is open 11 a.m.-5 p.m., Wednesday-Monday; Thursdays until 9 p.m. www.gardnermuseum.org, 617-566-1401.