The letter looked too regal to be taken seriously.

A redevelopment authority in Saudi Arabia’s capital city of Riyadh wanted Coen + Partners, a small landscape architecture firm in the North Loop of Minneapolis, to pitch ideas for a 1,220-acre public space in the King Abdullah Financial District.

“It sounded like a giant planning project that ends up on some government shelf and that never gets built,” said Shane Coen, the firm’s founder. “So we wrote back and said it isn’t really our cup of tea.”

The reply from Saudi Arabia was swift and direct: the park was one of the kingdom’s “most important urban projects” and it wanted Coen’s ideas.

The Arriyadh Development Authority flew the firm’s leaders to Riyadh for a three-day tour. On the last day, the firm presented a vision for the desert landscape following similar pitches from designers based in London or elsewhere in the Middle East. The 18-person firm from 1st Avenue N. made the biggest impression and was selected on the spot.

At first, Coen + Partners was hired to set the project’s design and cost estimates, which was completed in July. Last month, the High Commission approved the master plan and all zoning ordinances and are currently negotiating terms for Coen + Partners to lead the entire project.

Now, Coen + Partners is embarking on the largest — and most shocking — project in its history. The firm prides itself on creating “contextually” appropriate landscapes from private residences to large public spaces. And while it has experience in various U.S. locales and some international cities, such as Singapore and Shanghai, the physical and cultural environment of Saudi Arabia is unlike any place the firm has worked.

“This is a new type of development in Saudi Arabia,” Coen said. “They are entering a very interesting time in the Kingdom for a few reasons.”

Tension between old and new is at the heart the King Abdullah Financial District, which is designed to help Riyadh compete with Dubai as a regional business center. The district comprises more than 50 new towers and buildings that cost the Saudi government between $7 billion and $10 billion. Unlike the rest of Riyadh, men and women are not required to be separated in the district. And so Coen + Partners finds itself creating a more open and modern design for the public realm.

“Our park and public realm was designed for everyone. We intentionally did not differentiate uses,” Coen said.

The authority overseeing the development did not tell them to integrate everything, but the documents intentionally left out instructions to separate men and women.

“We always designed it as an open park and everyone embraced our recommendations all the way through the process,” Coen said.

The development authority has pushed the firm to do its best work, Coen said, and through the process, the client and company landed on boundary-pushing ideas. While most of the Riyadh is insular and reliant on cars, the design emphasizes walkable, social and pedestrian spaces.

“The government was really interested in embracing some of the aspects of the great Western neighborhoods like in New York, Portland and other transportation-oriented areas, which they have visited,” Coen said. “We really researched the culture and the context to bring forth a new idea for the residential neighborhood.”

Two key elements of the geography inspired much of the design: star-shaped sand dunes and the wadi, which is a dry valley that only flows with water when it rains. Arabian cities were established along wadis and are a sign of human and vegetative life within the country. The paths and homes will center around these mini-rivers. And by recycling and cleaning the water used in the buildings, the goal is to build the first desert botanical garden in Saudi Arabia on the site.

To provide shade, Coen + Partners designed a canopy of five massive, porous metal star dunes, each reaching the length of three Minneapolis city blocks.

If it were five years ago, Coen said, Saudi Arabia likely would have built the project all at once. But because oil prices collapsed, the country, one of the world’s largest oil producers, adopted austerity measures and construction on the financial district project slowed. The financial district is set to open within six months with nearly all of the towers complete or nearing completion. One similarity between this district and Coen’s hometown: skyways, or as they call them, skywalks.

Coen said he’s confident the project will get finished. “The city has already made an investment into the district,” he said.

With the first round of approvals given, Coen + Partners is now working with the government on its first logical step for the public space.

“It’s very interesting working there compared to U.S. cities where you have a lot of committees and there’s often more micromanaging going on,” Coen said. “Over there, they’ve hired you and they push you to do your very best work, but ultimately they trust you.”