Singapore’s spectacular skyline, which in this century has redefined itself with soaring structures, has a unique addition: Jewel Changi Airport.

The stunning, circular greenhouse-style gem was designed by Moshe Safdie, the architect of the city’s 38-acre, 57-story, 10 million-square-foot Marina Bay Sands resort and urban district, whose wonders include the ArtScience Museum. Safdie also designed the city’s Sky Habitat, a towering residential project linked by aerial walkways and connected streets, gardens, and terraces that opened in 2015.

The 81-year-old Safdie, who was born in Israel and moved to Canada when he was a teenager, has designed projects around the world, including the National Gallery of Canada in Ottawa and Canada’s Vancouver Library Square. Safdie Architects is based in Boston and has satellite offices in Jerusalem, Toronto, Shanghai, and Singapore.

And Jewel, which places retail shops in a “paradise garden,” is what Safdie calls “the heart and soul” of the airport, where some 65.6 million passengers pass through each year.

“Jewel weaves together an experience of nature and the marketplace, dramatically asserting the idea of the airport as an uplifting and vibrant urban center, engaging travelers, visitors, and residents and echoing Singapore’s reputation as ‘The City in the Garden,’” Safdie said in a statement at Jewel’s opening, which occurred in phases, starting in April 2019.

The public building, which links three airplane terminals via pedestrian bridges and is connected to a bus terminal, is designed to be an interactive civic plaza where passengers actually want to spend time and even nonfliers like to hang out.

The glass-enclosed, 1.46 million-square-foot structure, whose geometry is based on a semi-inverted toroidal- dome roof shaped like a doughnut, features a five-level retail marketplace.

The five-story Forest Valley is a terraced indoor garden with walking trails and seating areas set among more than 200 species of plants. The Rain Vortex, billed as the world’s tallest indoor waterfall, showers down seven stories from an oculus in the center of the roof.

The Canopy Park, which is on Jewel’s fifth level, features 150,694 square feet of interactive attractions, including bouncy net structures that hang from the trees, a glass-bottom bridge walk, a hedge maze, a mirror maze, a petal garden, slides for different age groups, and installations by acclaimed artists. There’s also a topiary walk, horticultural displays, and an event plaza that can accommodate 1,000 people.

The glass-and-steel domed roof is 650 feet at its widest point. More than 6,000 steel connectors, dubbed “Jewel nodes,” were prefabricated in Germany and bolted together in Singapore.

The Jewel is a subtle counterpoint to Safdie’s most significant Singapore project, Marina Bay Sands, which opened to great fanfare a decade ago.

The US$5.7-billion project, for the Las Vegas Sands Corp., includes a hotel with 2,560 luxury rooms whose three towers are connected at the top by a 107,000-square-foot park.

The project also has a four-level atrium-style casino whose ceiling centerpiece is a seven-ton Swarovski-crystal chandelier; retail and restaurant space; a convention center; two theaters; glass and steel pavilions that house shops and nightclubs; and the ArtScience Museum.

The museum is one of Safdie’s more curvaceous creations. It features 10 “fingers” set around a round base. Each finger houses a gallery; the “fingertips,” which are skylights, illuminate the curved interior walls.

“The flower-like geometry is one of the most complex we have designed,” Safdie said in a statement at its opening. As befitting a science museum, “it is highly mathematically ordered, for efficient construction. Some see the form of the museum as reminiscent of a lotus flower; others feel it looks like an open palm. For me, the museum’s design represents the forward-looking spirit of Singapore,” he said.

That spirit will be invigorated again in 2021, when Safdie’s Orchard Boulevard project opens. Located close to the city’s Orchard Road shopping district, its twin towers, which house private residences, are set above a boutique hotel on tall columns that offer unobstructed views in every direction. A dramatic garden courtyard connects the two.