More than a year after demolishing the beloved Prouty Garden to make room for a new tower, Boston Children’s Hospital is opening a new green space — a rooftop refuge for sick children, their families, and the staff who spend days and nights caring for them.

The 8,000-square-foot space is 11 stories up, on the hospital’s main building on Longwood Avenue. There are scattered reminders of the Prouty here — sculptures of a nurse and child, a fox, a frog — but this modern garden is not likely to be mistaken for its predecessor.

A floor of pavers and wood surrounds a lush grassy knoll. Young perennials and grasses are planted in perfect rows.

There are nosquirrels or bunnies or other critters here, as there were in the Prouty Garden. And there are no big trees.

But the new garden, which officially opens to patients Monday, offers sweeping views of the city skyline. From some angles, when clouds aren’t obscuring the view, children may be able to see a sliver of the harbor, and the ships rolling in and out.

Since the end of 2016, patients at Children’s Hospital have not had a place to go on campus to take a break from their medical treatment and feel the warmth of the sun.

“It’s beautiful, and I think it will be great for patients and families who are able to get out here and get some fresh air,’’ ICU nurse Elaine Feibelman said as she toured the space on a recent afternoon.

The rooftop garden is the first of several green spaces that hospital officials plan to open over the next several years as part of a $1 billion expansion and renovation of the campus slated to be complete in 2022. They plan to build another smaller rooftop garden, two indoor gardens, and a 14,000-square-foot, ground-level garden.

The biggest change to the campus will be the construction of an 11-story tower housing new patient rooms and operating rooms. Hospital officials say the new building will allow them to serve more patients and to offer more privacy to existing patients who now have to share rooms.

The tower will be on the site of the former Prouty Garden, a tranquil half-acre space cherished by many families and staff. Parents sought solace in the garden with their children when the children were sick or dying.

“The Prouty Garden will always live in all of our hearts as a special place,’’ said Judy Mahoney, a nurse manager who has worked at the hospital for 39 years. “It was really hard for us to move on from that. It was a little jewel in the middle of the city of Boston.’’

But Mahoney, who works with infants and toddlers, said the new building is needed to help patients and their families. She said she tells parents: “If I could build that hospital faster, I would.’’

Gus Murby, who was part of a group that fought the demolition of Prouty Garden, said he was disappointed after viewing pictures of the new rooftop garden. He called it “sterile’’ and “soulless.’’

Murby visited the Prouty Garden with his son when the teenager was dying from leukemia in 2007. He is the lead plaintiff in an ongoing lawsuit that contends the hospital should not have been granted state approval to construct a new tower.

“That’s not a healing garden,’’ Murby said, “it’s kind of like a deck of a cruise ship where people can go out and have lunch.’’

Lisa Hogarty, senior vice president of real estate planning and development at the hospital, said the rooftop garden was designed to withstand severe weather and to be welcoming for children, particularly kids in wheelchairs and those with compromised immune systems. The mulch, for example, is made from the shredded rubber of recycled car tires, which is safe for children with allergies.

There are bright-colored tables and chairs where visitors can sit in the sun, and more private benches in the shade.

“These gardens are meant to promote healing and health and offer respite for the patients and their families,’’ Hogarty said.

Nurses who got an early glimpse of the new garden said they were excited to have a place to take a break and to bring their young patients.

“It does feel a little bit smaller [than the Prouty], but it’s still gorgeous,’’ said Michelle Audain, an ICU nurse.

Three-year-old Jake Moulton from Danvers, who was at the hospital recovering from tonsil surgery and other procedures, was the first patient to visit the garden. The boy climbed up on a bench to get a good view of the city and pointed excitedly to the buildings all around, as his parents followed with his IV bag.

“It’s a nice break from the hospital,’’ said his father, Steve Moulton, “that’s for sure.’’

Priyanka Dayal McCluskey can be reached at priyanka.mccluskey @globe.com. Follow her on Twitter @priyanka_dayal.