See what the 14-acre park designed to top two freeway tunnels in S.F. will look like

Gateway Plaza "The social and connective center of the park, hosts the newly renovated Visitor Center and Transit Center, the latter of which serves as the primary method for visitors to arrive at the Presidio via public transit to begin their visit," according to press materials. less Gateway Plaza "The social and connective center of the park, hosts the newly renovated Visitor Center and Transit Center, the latter of which serves as the primary method for visitors to arrive at the Presidio ... more Photo: James Corner Field Operations Photo: James Corner Field Operations Image 1 of / 23 Caption Close See what the 14-acre park designed to top two freeway tunnels in S.F. will look like 1 / 23 Back to Gallery

The tops of two freeway tunnels in San Francisco are on the verge of being transformed.

Phase one of construction began this week on a 14-acre park that will stretch over the Presidio Parkway tunnels, reforming a connection between Crissy Field and the Presidio's Main Outpost that was broken when Doyle Drive was built in 1936 to provide a link between central San Francisco and the Golden Gate Bridge.

The project was designed by New York City-based landscape architecture firm James Corner Field Operations, whose urban public projects include New York’s High Line, Chicago’s Navy Pier and Seattle’s Central Waterfront.

“The iconic setting is perfect for transforming highway infrastructure into a vibrant new public space,” said lead architect James Corner.

Renderings released this week of the so-called Tunnel Tops show a vast expanse of native vegetation with walking pathways and scenic overlooks for taking in wide views of the Bay and Golden Gate Bridge. There's also a campfire circle for ranger talks, a massive meadow perfect for kite-flying and picnics, a bluff walk passing windswept pines and a children's playground for ages two to 13. A Youth Campus will focus on teaching kids environmental stewardship.

“The Tunnel Tops will provide greater access to fresh air, beautiful views, gardens, and gathering spaces where people can come to relax, play and connect with each other," said Jean Fraser, CEO of the Presidio Trust. "Having a national park so close to downtown is part of what makes San Francisco great, and we hope it will inspire new visitors to discover the many things the Presidio, the Golden Gate National Recreation Area, and other national parks have to offer.”

More than 10,000 community members provided input in the park's collaborative design.

The project has been five years in the making and is projected to open in 2021.

Amy Graff is a digital editor for SFGATE. Email her at agraff@sfgate.com.