By covering the base of the buildings in earth, Ma and his team were able to minimize exposed facades and establish a “thermo-regulator” that reduces solar loads and the amount of energy needed to heat and cool the interiors. They also created an architecture that people can climb and use as public green space, even when the buildings are closed. Pedestrian and bike paths wind from one facility to another, while a shared basement will connect the under-construction gym, natatorium, and training center (but not the stadium) below ground when they are completed. Working with landscape architect Peter Walker, Ma’s firm specified four different kinds of grass, depending on the angle and orientation of the sloping terrain enveloping the structures. Walker also proposed planting thousands of sequoia trees around the three-mile perimeter to create “a linear forest,” says Ma. The trees are now in place and will grow into a leafy buffer between city and sports campus. Once farmland and fish ponds, the park is now part of a rapidly developing area of Quzhou, with low- and mid-rise residential buildings, as well as mixed-use structures. MAD and Walker’s firm, the Berkeley, California–based PWP Landscape Architecture, used the water on-site to create a lake and landscaped the grounds to act as a sponge to absorb rainwater, filter it, and release it when needed.

For the stadium, the largest building in the park, Ma envisioned a volcano, with a crater in the center. “I wanted something mysterious, something that would talk to the sky and the universe,” he says. While the base is sheltered by sloping, grass-covered roofs, the architects punched large openings into them to bring daylight and air to the parking and entry levels of the stadium. A poured-in-place concrete structure supports a saddle-shaped bowl for seating. The structure’s enormous arches and curving columns, along with the oval-shaped openings in the base, establish a dynamic visual rhythm as visitors walk through the promenades around the stadium. The exposed concrete frame, with its sculpted supporting members, might make Pier Luigi Nervi proud.

To protect the seating areas from sun and rain, the architects at MAD and engineers at the Stuttgart-based firm Schlaich Bergermann Partners designed a steel-and-translucent-fabric “halo” that seems to hover above the concrete bowl, dipping down at one end to open views to the rest of the park. Wrapped with a synthetic-polymer membrane called PTFE, the steel-truss halo rests on nine columns, with the longest span stretching to 312 feet. Lights attached to the underside of the canopy provide most of the illumination, while a pair of antennae-like stanchions punch through the covering where it dips down.

The stadium is now open, while the gym, natatorium, and ancillary facilities are scheduled to be completed in two years. The science and technology center will be built later. Each building will have its own character, but all will have openings and skylights to bring light and air inside their earth-sheltered forms.

MAD recently completed a large train station and outdoor plaza in Jiaxing, 200 miles northeast of Quzhou, so Ma has been studying the way people move in public spaces. “Everyone is rushing from one place to another,” he notes. With the Quzhou stadium and sports park, “I wanted to create continuous movement between indoors and out,” using the earth as both a material and a threshold. He hopes the park will offer people a place to slow down and escape the pressures they feel elsewhere.